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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
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Clonidine may be used in combination with benzodiazepines to help some of the symptoms. There is insufficient evidence to support the use of baclofen for alcohol withdrawal syndrome.
Antipsychotics, such as haloperidol, are sometimes used in addition to benzodiazepines to control agitation or psychosis. Antipsychotics may potentially worsen alcohol withdrawal as they lower the seizure threshold. Clozapine, olanzapine, or low-potency phenothiazines (such as chlorpromazine) are particularly risky; if used, extreme caution is required.
While intravenous ethanol could theoretically be used, evidence to support this use, at least in those who are very sick, is insufficient.
Very limited evidence indicates that topiramate or pregabalin may be useful in the treatment of alcohol withdrawal syndrome. Limited evidence supports the use of gabapentin or carbamazepine for the treatment of mild or moderate alcohol withdrawal as the sole treatment or as combination therapy with other medications; however, gabapentin does not appear to be effective for treatment of severe alcohol withdrawal and is therefore not recommended for use in this setting. A 2010 Cochrane review similarly reported that the evidence to support the role of anticonvulsants over benzodiazepines in the treatment of alcohol withdrawal is not supported. Paraldehyde combined with chloral hydrate showed superiority over chlordiazepoxide with regard to life-threatening side effects and carbamazepine may have advantages for certain symptoms.
Cognitive behavioral therapy has been found to be more effective for the long-term management of insomnia than sedative hypnotic drugs. No formal withdrawal programs for benzodiazepines exists with local providers in the UK. Meta-analysis of published data on psychological treatments for insomnia show a success rate between 70 and 80%. A large-scale trial utilizing cognitive behavioral therapy in chronic users of sedative hypnotics including nitrazepam, temazepam, and zopiclone found CBT to be a significantly more effective long-term treatment for chronic insomnia than sedative hypnotic drugs. Persisting improvements in sleep quality, sleep onset latency, increased total sleep, improvements in sleep efficiency, significant improvements in vitality, physical and mental health at 3-, 6-, and 12-month follow-ups were found in those receiving CBT. A marked reduction in total sedative hypnotic drug use was found in those receiving CBT, with 33% reporting zero hypnotic drug use. Age has been found not to be a barrier to successful outcome of CBT. It was concluded that CBT for the management of chronic insomnia is a flexible, practical, and cost-effective treatment, and it was also concluded that CBT leads to a reduction of benzodiazepine drug intake in a significant number of patients. Chronic use of hypnotic medications is not recommended due to their adverse effects on health and the risk of dependence. A gradual taper is usual clinical course in getting people off of benzodiazepines, but, even with gradual reduction, a large proportion of people fail to stop taking benzodiazepines. The elderly are particularly sensitive to the adverse effects of hypnotic medications. A clinical trial in elderly people dependent on benzodiazepine hypnotics showed that the addition of CBT to a gradual benzodiazepine reduction program increased the success rate of discontinuing benzodiazepine hypnotic drugs from 38% to 77% and at the 12-month follow-up from 24% to 70%. The paper concluded that CBT is an effective tool for reducing hypnotic use in the elderly and reducing the adverse health effects that are associated with hypnotics such as drug dependence, cognitive impairments, and increased road traffic accidents.
A study of patients undergoing benzodiazepine withdrawal who had a diagnosis of generalized anxiety disorder showed that those having received CBT had a very high success rate of discontinuing benzodiazepines compared to those not having receive CBT. This success rate was maintained at the 12-month follow-up. Furthermore, it was found that, in patients having discontinued benzodiazepines, they no longer met the diagnosis of general anxiety disorder, and that the number of patients no longer meeting the diagnosis of general anxiety disorder was higher in the group having received CBT. Thus, CBT can be an effective tool to add to a gradual benzodiazepine dosage reduction program leading to improved and sustained mental health benefits (Disputed).
Naltrexone is used for the treatment of opioid addiction. It works by blocking the physiological, euphoric, and reinforcing effects of opioids. Non-compliance with naltrexone therapy is a concern with oral formulations because of its daily dosing, and although the alternative intramuscular (IM) injection has better compliance due to its monthly dosing, attempts to override the blocking effect with higher doses and stronger drugs have proven dangerous. Naltrexone monthly IM injections received FDA approval in 2010 for the treatment of opioid dependence in abstinent opioid users.
Buprenorphine sublingual preparations are often used to manage opioid dependence (that is, dependence on heroin, oxycodone, hydrocodone, morphine, oxymorphone, fentanyl or other opioids). Preparations were approved for this indication by the United States Food and Drug Administration in October 2002. Some formulations of buprenorphine incorporate the opiate antagonist naloxone during the production of the pill form to prevent people from crushing the tablets and injecting them, instead of using the sublingual (under the tongue) route of administration.
Flumazenil is being studied as a potential treatment to reduce withdrawal symptoms. As its use may result in seizures this should only be done within hospital in areas experienced with the procedure.
A related issue is overprescription, which occurs when doctors give prescription drugs to patients who do not need them. Antibiotics are a common example, as are narcotic painkillers. Aggressive marketing by drug companies is sometimes cited as a reason for overprescription.
Flumazenil (Romazicon) is a competitive benzodiazepine receptor antagonist that can be used as an antidote for benzodiazepine overdose. Its use, however, is controversial as it has numerous contraindications. It is contraindicated in patients who are on long-term benzodiazepines, those who have ingested a substance that lowers the seizure threshold, or in patients who have tachycardia, widened QRS complex on ECG, anticholinergic signs, or a history of seizures. Due to these contraindications and the possibility of it causing severe adverse effects including seizures, adverse cardiac effects, and death, in the majority of cases there is no indication for the use of flumazenil in the management of benzodiazepine overdose as the risks in general outweigh any potential benefit of administration. It also has no role in the management of unknown overdoses. In addition, if full airway protection has been achieved, a good outcome is expected, and therefore flumazenil administration is unlikely to be required.
Flumazenil is very effective at reversing the CNS depression associated with benzodiazepines but is less effective at reversing respiratory depression. One study found that only 10% of the patient population presenting with a benzodiazepine overdose are suitable candidates for flumazenil. In this select population who are naive to and overdose solely on a benzodiazepine, it can be considered. Due to its short half life, the duration of action of flumazenil is usually less than 1 hour, and multiple doses may be needed. When flumazenil is indicated the risks can be reduced or avoided by slow dose titration of flumazenil. Due to risks and its many contraindications, flumazenil should be administered only after discussion with a medical toxicologist.
Supportive measures include observation of vital signs, especially Glasgow Coma Scale and airway patency. IV access with fluid administration and maintenance of the airway with intubation and artificial ventilation may be required if respiratory depression or pulmonary aspiration occurs. Supportive measures should be put in place prior to administration of any benzodiazepine antagonist in order to protect the patient from both the withdrawal effects and possible complications arising from the benzodiazepine. A determination of possible deliberate overdose should be considered with appropriate scrutiny, and precautions taken to prevent any attempt by the patient to commit further bodily harm. Hypotension is corrected with fluid replacement, although catecholamines such as norepinephrine or dopamine may be required to increase blood pressure. Bradycardia is treated with atropine or an infusion of norepinephrine to increase coronary blood flow and heart rate.
The overmedication of children has dramatically risen with those between the ages of 2 and 5 years old who are being prescribed atypical antipsychotics for bipolar disorders, developmental disabilities, ADHD, and behavior disorders. Drug companies have benefited considerably with profits made in sales for drugs such as stimulants for hyperactive children, with half a million children in the United States receiving medication. Children have become more involved with technology resulting in less play time outside and less time spent with parents. The long hours children spend with technology has impacted their attachment development, sensory and motor development, along with socialization skills, in return causing behavioral and psychological disorders and learning disabilities being diagnosed by psychotropic medication.
According to recent data from IMS health one of the leading services for data distribution in health care, 274,000 infants (0 to 1) are on anti-anxiety drugs, and 26,000 under a year old are on antidepressants. This is only a fraction of the millions of children 5 to 12 being prescribed these same drugs.
While these drugs can provide relief from some symptoms the children may suffer, psychiatric drugs have been shown in some instances to worsen the symptoms of mental illness and can cause adverse physical effects such as liver damage, weight gain, decreased cognitive function and dependency on the drug. (1) Antidepressants have side effects that can include suicidal thoughts and worsening depression. These medications can have long lasting effects on the children and these risks need to be taken into consideration.
It's important for parents to monitor their child's behavior and regulate their environment in order to help prevent any future affective disorders. Medication is often prescribed to these children however, it alone will not teach a child to create more valuable relationships at home or in the community. Other forms of intervention can be applied to supplement the effects of medication therapy and teach the child self-regulatory behaviors and healthy coping skills. The increase of psychiatric medication of children may be a result of the declining support for caregiving, leading to psychopathology in which drugs are oftentimes the go to method of treatment. Families do not always have knowledge regarding or the means to pursue other methods of intervention such as one-on-one therapy with the child, family therapy and parenting counseling that can teach effective parenting strategies to meet their child's specific needs. There is debate that healthcare professionals have been put under pressure to perform proficiently causing the influence of piecemeal polypharmacy.
Behavioral tolerance occurs with the use of certain psychoactive drugs, where tolerance to a behavioral effect of a drug, such as increased motor activity by methamphetamine, occurs with repeated use; it may occur through drug-independent learning or as a form of pharmacodynamic tolerance in the brain; the latter mechanism of behavioral tolerance occurs when one learns how to actively overcome drug-induced impairment through practice. Behavioral tolerance is often context-dependent, meaning tolerance depends on the environment in which the drug is administered, and not on the drug itself. Behavioral sensitization describes the opposite phenomenon.
Tachyphylaxis is a subcategory of drug tolerance referring to cases of sudden, short-term onset of tolerance following the administration of a drug.
Over the counter medications are those medications that do not require a prescription to purchase in the US. Medications that require a prescription to purchase in the US may be available in other countries without a prescription. The following guidelines are recommended:
- taking oral medications after breastfeeding rather than before will allow some of the medication to leave the mother's body through her kidneys between nursings.
- in most women without kidney disease, nonsteroidal anti-inflammatory drugs and paracetamol (acetaminophen) are used safely.
- aspirin can cause rashes and even cause bleeding in infants.
- limit the use of antihistamines for long periods of time. These anti-allergy medications can cause crying, sleep problems, fussiness, exsessive sleepiness in babies. Antihistamines have an effect on the amount of milk the body produces and decrease the supply.
- carefully observe the infant for changes or side effects when first taking a medication to watch for side effects. Side effects indicating that the medication is having an affect on the baby is difficulty breathing, rash and other questionable changes that occurred after the medication was started by the mother.
- many times other young children are in the home and keeping these over the counter medications out of their reach is a safe practice.
Other substances or chemicals have been evaluated regarding their safe use during pregnancy. Hair dye or solutions used for a 'permanent' do not pass to breastmilk. No adverse reports of using oral antihastamines and breastfeeding are found. Some of the older antihistamines used by a nursing mother can cause drowsiness in the infant. This may be a concern if the infant misses feedings by sleeping instead of nursing.
Fluoxetine, an SSRI used by humans under the brand name Prozac, is now prescribed to dogs under the brand name Reconcile. Another study found that dogs who were being treated with both Reconcile and Behavioral Modulation Treatment compared to dogs receiving a placebo and behavioral therapy called Behavior Modulation Treatment, were much more successful at mitigating behaviors related to separation anxiety. After 8 weeks of treatment, 72% of the dogs given fluoxetine displayed fewer adverse behaviors (e.g., excessive salivation, inappropriate urination/defecation) while only 50% of the placebo group had mitigated these behaviors.
In another study conducted in 2015, dogs expressing symptoms of separation anxiety were given fluoxetine tablets and a standard behavior modification plan for two months. Owner interviews, spatial cognitive bias tests, questionnaires and relations between cognitive bias and drug treatment were all taken into consideration. Results showed that the clinical treatment of fluoxetine seemed to produce a shift in cognitive bias in the canine subjects, emphasizing that pharmacological therapy not only can positively affect behavior, but also an animal's psychological state.
Generally, a person experiencing a psychedelic crisis can be helped either to resolve the impasse, to bypass it, or, failing that, to terminate the experience. A person's thoughts before taking or while under the influence of the psychedelic, often greatly influence the trip.
Medical treatment consists of supportive therapy and minimization of external stimuli. In some cases, sedation is used when necessary to control self-destructive behavior, or when hyperthermia occurs. Diazepam is the most frequently used sedative for such treatment, but other benzodiazepines such as lorazepam are also effective. Such sedatives will only decrease fear and anxiety, but will not subdue hallucinations. In severe cases, antipsychotics such as haloperidol can reduce or stop hallucinations. Haloperidol is effective against drug-induced psychosis caused by LSD and other tryptamines, amphetamines, ketamine and phencyclidine.
Complications of benzodiazepine abuse include drug-related deaths due to overdose especially in combination with other depressant drugs such as opioids. Other complications include: blackouts and memory loss, paranoia, violence and criminal behaviour, risk-taking sexual behaviour, foetal and neonatal risks if taken in pregnancy, dependence, withdrawal seizures and psychosis. Injection of the drug carries risk of: thrombophlebitis, deep vein thrombosis, deep and superficial abscesses, pulmonary microembolism, rhabdomyolysis, tissue necrosis, gangrene requiring amputation, hepatitis B and C, as well as blood borne infections such as HIV infection (caused by sharing injecting equipment). Long-term use of benzodiazepines can worsen pre-existing depression and anxiety and may potentially also cause dementia with impairments in recent and remote memory functions.
Use is widespread among amphetamine users, with those that use amphetamines and benzodiazepines having greater levels of mental health problems and social deterioration. Benzodiazepine injectors are almost four times more likely to inject using a shared needle than non-benzodiazepine-using injectors. It has been concluded in various studies that benzodiazepine use causes greater levels of risk and psycho-social dysfunction among drug misusers.
Poly-drug users who also use benzodiazepines appear to engage in more frequent high-risk behaviors. Those who use stimulant and depressant drugs are more likely to report adverse reactions from stimulant use, more likely to be injecting stimulants and more likely to have been treated for a drug problem than those using stimulant but not depressant drugs.
Dogs can also be treated with psychotropic drugs, such as anti-depressants or anti-anxiety drugs.
A recent trend in treatment is the use of psychotropic drugs in animals to treat similar psychological disorders to those displayed in humans and mitigate the behavior related to these disorders. These connections between human and animal psychopharmacology can help to explain how similar neurobiology can be among different species.
Similar to humans, Selective Serotonin Reuptake Inhibitors, or SSRIs, or tricyclic anti-depressants are used to treat anxious and depressive behavior in animals. One study tracked the effectiveness of clomipramine, a tricyclic anti-depressant, in reducing compulsive behaviors through administration of a tricyclic anti-depressant in dogs. Behaviors displayed by these dogs include but are not limited to tail-chasing, shadow-chasing, circling and chewing. The study found that after one month of daily administration of the tricyclic anti-depressant clomipramine, these compulsive behaviors decreased or disappeared in 16 out of 24 dogs. Slight to moderate behavior mitigation was shown in 5 dogs. These results suggest that clomipramine can be beneficial to canines displaying anxiety behaviors.
Anxiety disorders can also be treated with dog-appeasing pheromones similar to those given off by their mothers. The pheromone containing products are sold in collars and sprays under the brand name Adaptil.
Benzodiazepines are a commonly abused class of drugs, although there is debate as to whether certain benzodiazepines have higher abuse potential than others. In animal and human studies the abuse potential of benzodiazepines is classed as moderate in comparison to other drugs of abuse.
Benzodiazepines are commonly abused by poly drug users, especially heroin addicts, alcoholics or amphetamine addicts when "coming down". but sometimes are misused in isolation as the primary drug of misuse. They can be misused to achieve the high that benzodiazepines produce or more commonly they are used to either enhance the effects of other CNS depressant drugs, to stave off withdrawal effects of other drugs or combat the effects of stimulants. As many as 30–50% of alcoholics are also benzodiazepine misusers. Drug abusers often abuse high doses which makes serious benzodiazepine withdrawal symptoms such as psychosis or convulsions more likely to occur during withdrawal.
Benzodiazepine abuse increases risk-taking behaviors such as unprotected sex and sharing of needles amongst intravenous abusers of benzodiazepines. Abuse is also associated with blackouts, memory loss, aggression, violence, and chaotic behavior associated with paranoia. There is little support for long-term maintenance of benzodiazepine abusers and thus a withdrawal regime is indicated when benzodiazepine abuse becomes a dependence. The main source of illicit benzodiazepines are diverted benzodiazepines obtained originally on prescription; other sources include thefts from pharmacies and pharmaceutical warehouses. Benzodiazepine abuse is steadily increasing and is now a major public health problem. Benzodiazepine abuse is mostly limited to individuals who abuse other drugs, i.e. poly-drug abusers. Most prescribed users do not abuse their medication, however, some high dose prescribed users do become involved with the illicit drug scene. Abuse of benzodiazepines occurs in a wide age range of people and includes teenagers and the old. The abuse potential or drug-liking effects appears to be dose related, with low doses of benzodiazepines having limited drug liking effects but higher doses increasing the abuse potential/drug-liking properties.
Alcoholics may also require treatment for other psychotropic drug addictions and drug dependences. The most common dual dependence syndrome with alcohol dependence is benzodiazepine dependence, with studies showing 10–20 percent of alcohol-dependent individuals had problems of dependence and/or misuse problems of benzodiazepine drugs such as valium or clonazopam. These drugs are, like alcohol, depressants. Benzodiazepines may be used legally, if they are prescribed by doctors for anxiety problems or other mood disorders, or they may be purchased as illegal drugs "on the street" through illicit channels. Benzodiazepine use increases cravings for alcohol and the volume of alcohol consumed by problem drinkers. Benzodiazepine dependency requires careful reduction in dosage to avoid benzodiazepine withdrawal syndrome and other health consequences. Dependence on other sedative-hypnotics such as zolpidem and zopiclone as well as opiates and illegal drugs is common in alcoholics. Alcohol itself is a sedative-hypnotic and is cross-tolerant with other sedative-hypnotics such as barbiturates, benzodiazepines and nonbenzodiazepines. Dependence upon and withdrawal from sedative-hypnotics can be medically severe and, as with alcohol withdrawal, there is a risk of psychosis or seizures if not managed properly.
Some drugs, such as the prokinetic agents increase the speed with which a substance passes through the intestines. If a drug is present in the digestive tract's absorption zone for less time its blood concentration will decrease. The opposite will occur with drugs that decrease intestinal motility.
- pH: Drugs can be present in either ionised or non-ionised form, depending on their pKa (pH at which the drug reaches equilibrium between its ionised and non-ionised form). The non-ionized forms of drugs are usually easier to absorb, because they will not be repelled by the lipidic bylayer of the cell, most of them can be absorbed by passive diffusion, unless they are too big or too polarized (like glucose or vancomicyn), in which case they may have or not specific and non specific transporters distributed on the entire intestine internal surface, that carries drugs inside the body. Obviously increasing the absorption of a drug will increase its bioavailability, so, changing the drug's state between ionized or not, can be useful or not for certain drugs.
Certain drugs require an acid stomach pH for absorption. Others require the basic pH of the intestines. Any modification in the pH could change this absorption. In the case of the antacids, an increase in pH can inhibit the absorption of other drugs such as zalcitabine (absorption can be decreased by 25%), tipranavir (25%) and amprenavir (up to 35%). However, this occurs less often than an increase in pH causes an increase in absorption. Such as occurs when cimetidine is taken with didanosine. In this case a gap of two to four hours between taking the two drugs is usually sufficient to avoid the interaction.
- Drug solubility: The absorption of some drugs can be drastically reduced if they are administered together with food with a high fat content. This is the case for oral anticoagulants and avocado.
- Formation of non-absorbable complexes:
- Chelation: The presence of di- or trivalent cations can cause the chelation of certain drugs, making them harder to absorb. This interaction frequently occurs between drugs such as tetracycline or the fluoroquinolones and dairy products (due to the presence of Ca).
- Binding with proteins. Some drugs such as sucralfate binds to proteins, especially if they have a high bioavailability. For this reason its administration is contraindicated in enteral feeding.
- Finally, another possibility is that the drug is retained in the intestinal lumen forming large complexes that impede its absorption. This can occur with cholestyramine if it is associated with sulfamethoxazol, thyroxine, warfarin or digoxin.
- Acting on the P-glycoprotein of the enterocytes: This appears to be one of the mechanisms promoted by the consumption of grapefruit juice in increasing the bioavailability of various drugs, regardless of its demonstrated inhibitory activity on first pass metabolism.
The initial treatment of nicotine poisoning may include the administration of activated charcoal to try to reduce gastrointestinal absorption. Treatment is mainly supportive and further care can include control of seizures with the administration of a benzodiazepine, intravenous fluids for hypotension, and administration of atropine for bradycardia. Respiratory failure may necessitate respiratory support with rapid sequence induction and mechanical ventilation. Hemodialysis, hemoperfusion or other extracorporeal techniques do not remove nicotine from the blood and are therefore not useful in enhancing elimination. Acidifying the urine could theoretically enhance nicotine excretion, although this is not recommended as it may cause complications of metabolic acidosis.
In the United States there are four approved medications for alcoholism: disulfiram, two forms of naltrexone, and acamprosate. Several other drugs are also used and many are under investigation.
- Benzodiazepines, while useful in the management of acute alcohol withdrawal, if used long-term can cause a worse outcome in alcoholism. Alcoholics on chronic benzodiazepines have a lower rate of achieving abstinence from alcohol than those not taking benzodiazepines. This class of drugs is commonly prescribed to alcoholics for insomnia or anxiety management. Initiating prescriptions of benzodiazepines or sedative-hypnotics in individuals in recovery has a high rate of relapse with one author reporting more than a quarter of people relapsed after being prescribed sedative-hypnotics. Those who are long-term users of benzodiazepines should not be withdrawn rapidly, as severe anxiety and panic may develop, which are known risk factors for relapse into alcohol abuse. Taper regimes of 6–12 months have been found to be the most successful, with reduced intensity of withdrawal.
- Acamprosate may stabilise the brain chemistry that is altered due to alcohol dependence via antagonising the actions of glutamate, a neurotransmitter which is hyperactive in the post-withdrawal phase. By reducing excessive NMDA activity which occurs at the onset of alcohol withdrawal, acamprosate can reduce or prevent alcohol withdrawal related neurotoxicity. Acamprosate reduces the risk of relapse amongst alcohol dependent persons.
- Disulfiram (Antabuse) prevents the elimination of acetaldehyde, a chemical the body produces when breaking down ethanol. Acetaldehyde itself is the cause of many hangover symptoms from alcohol use. The overall effect is severe discomfort when alcohol is ingested: an extremely fast-acting and long-lasting uncomfortable hangover. This discourages an alcoholic from drinking in significant amounts while they take the medicine.
- Naltrexone is a competitive antagonist for opioid receptors, effectively blocking the effects of endorphins and opioids. Naltrexone is used to decrease cravings for alcohol and encourage abstinence. Alcohol causes the body to release endorphins, which in turn release dopamine and activate the reward pathways; hence when naltrexone is in the body there is a reduction in the pleasurable effects from consuming alcohol. Evidence supports a reduced risk of relapse among alcohol dependent persons and a decrease in excessive drinking. Nalmefene also appears effective and works by a similar manner.
- Calcium carbimide works in the same way as disulfiram; it has an advantage in that the occasional adverse effects of disulfiram, hepatotoxicity and drowsiness, do not occur with calcium carbimide.
The Sinclair method is a method of using naltrexone or another opioid antagonists to treat alcoholism by having the person take the medication about an hour before they drink alcohol, and only then. The medication blocks the positive reinforcement effects of ethanol and hopefully allows the person to stop drinking or drink less.
Evidence does not support the use of selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), antipsychotics, or gabapentin.
Causality assessment is used to determine the likelihood that a drug caused a suspected ADR. There are a number of different methods used to judge causation, including the Naranjo algorithm, the Venulet algorithm and the WHO causality term assessment criteria. Each have pros and cons associated with their use and most require some level of expert judgement to apply.
An ADR should not be labeled as 'certain' unless the ADR abates with a challenge-dechallenge-rechallenge protocol (stopping and starting the agent in question). The chronology of the onset of the suspected ADR is important, as another substance or factor may be implicated as a cause; co-prescribed medications and underlying psychiatric conditions may be factors in the ADR.
Assigning causality to a specific agent often proves difficult, unless the event is found during a clinical study or large databases are used. Both methods have difficulties and can be fraught with error. Even in clinical studies some ADRs may be missed as large numbers of test individuals are required to find that adverse drug reaction. Psychiatric ADRs are often missed as they are grouped together in the questionnaires used to assess the population.
An example of synergism is two drugs that both prolong the QT interval.
Among US adults older than 55, 4% are taking medication and or supplements that put them at risk of a major drug interaction. Potential drug-drug interactions have increased over time and are more common in the low educated elderly even after controlling for age, sex, place of residence, and comorbidity.