Following an acute overdose of a benzodiazepine the onset of symptoms is typically rapid with most developing symptoms within 4 hours. Patients initially present with mild to moderate impairment of central nervous system function. Initial signs and symptoms include intoxication, somnolence, diplopia, impaired balance, impaired motor function, anterograde amnesia, ataxia, and slurred speech. Most patients with pure benzodiazepine overdose will usually only exhibit these mild CNS symptoms. Paradoxical reactions such as anxiety, delirium, combativeness, hallucinations, and aggression can also occur following benzodiazepine overdose. Gastrointestinal symptoms such as nausea and vomiting have also been occasionally reported.

Cases of severe overdose have been reported and symptoms displayed may include prolonged deep coma or deep cyclic coma, apnea, respiratory depression, hypoxemia, hypothermia, hypotension, bradycardia, cardiac arrest, and pulmonary aspiration, with the possibility of death. Severe consequences are rare following overdose of benzodiazepines alone but the severity of overdose is increased significantly if benzodiazepines are taken in overdose in combination with other medications. Significant toxicity may result following recreation drug misuse in conjunction with other CNS depressants such as opioids or ethanol. The duration of symptoms following overdose is usually between 12 and 36 hours in the majority of cases. The majority of drug-related deaths involve misuse of heroin or other opioids in combination with benzodiazepines or other CNS depressant drugs. In most cases of fatal overdose it is likely that lack of opioid tolerance combined with the depressant effects of benzodiazepines is the cause of death.

The symptoms of an overdose such as sleepiness, agitation and ataxia occur much more frequently and severely in children. Hypotonia may also occur in severe cases.

Benzodiazepines have a wide therapeutic index and taken alone in overdose rarely cause severe complications or fatalities. More often than not, a patient who inadvertently takes more than the prescribed dose will simply feel drowsy and fall asleep for a few hours. Benzodiazepines taken in overdose in combination with alcohol, barbiturates, opioids, tricyclic antidepressants, or sedating antipsychotics, anticonvulsants, or antihistamines are particularly dangerous. In the case of alcohol and barbiturates, not only do they have an additive effect but they also increase the binding affinity of benzodiazepines to the benzodiazepine binding site, which results in a very significant potentiation of the CNS and respiratory depressant effects. In addition, the elderly and those with chronic illnesses are much more vulnerable to lethal overdose with benzodiazepines. Fatal overdoses can occur at relatively low doses in these individuals.

Signs and symptoms of an overdose vary depending on the drug or toxin exposure. The symptoms can often be divided into differing toxidromes. This can help one determine what class of drug or toxin is causing the difficulties.

Symptoms of opioid overdoses include slow breathing, heart rate and pulse. Opioid overdoses can also cause pinpoint pupils, and blue lips and nails due to low levels of oxygen in the blood. A person experiencing an opioid overdose might also have muscle spasms, seizures and decreased consciousness. A person experiencing an opiate overdose usually will not wake up even if their name is called or if they are shaken vigorously.

Opioids, because of their effect on the part of the brain that regulates breathing, can during overdoses lead to the person not breathing (respiratory depression) and therefore result in death. Opiate overdose symptoms and signs can be referred to as the "opioid overdose triad": decreased level of consciousness, pinpoint pupils and respiratory depression. Other symptoms include seizures and muscle spasms. Sometimes a person experiencing an opiate overdose can lead to such a decreased level of consciousness that he or she won't even wake up to their name being called or being shaken by another person.

Prolonged hypoxia from respiratory depression can also lead to detrimental damage to the brain and spinal cord and can leave the person unable to walk or function normally, even if treatment with naloxone is given.

Alcohol also causes respiratory depression and therefore when taken with opioids can increase the risk of respiratory depression and death.

The main symptoms of delirium tremens are nightmares, agitation, global confusion, disorientation, visual and auditory hallucinations, tactile hallucinations, fever, high blood pressure, heavy sweating, and other signs of autonomic hyperactivity (fast heart rate and high blood pressure). These symptoms may appear suddenly, but typically develop two to three days after the stopping of heavy drinking, being worst on the fourth or fifth day. Also, these "symptoms are characteristically worse at night". In general, DT is considered the most severe manifestation of alcohol withdrawal and occurs 3–10 days following the last drink. Other common symptoms include intense perceptual disturbance such as visions of insects, snakes, or rats. These may be hallucinations, or illusions related to the environment, e.g., patterns on the wallpaper or in the peripheral vision that the patient falsely perceives as a resemblance to the morphology of an insect, and are also associated with tactile hallucinations such as sensations of something crawling on the subject—a phenomenon known as formication. Delirium tremens usually includes extremely intense feelings of "impending doom". Severe anxiety and feelings of imminent death are common DT symptoms.

DT can sometimes be associated with severe, uncontrollable tremors of the extremities and secondary symptoms such as anxiety, panic attacks and paranoia. Confusion is often noticeable to onlookers as those with DT will have trouble forming simple sentences or making basic logical calculations.

DT should be distinguished from alcoholic hallucinosis, the latter of which occurs in approximately 20% of hospitalized alcoholics and does not carry a significant mortality. In contrast, DT occurs in 5–10% of alcoholics and carries up to 15% mortality with treatment and up to 35% mortality without treatment. DT is characterized by the presence of altered sensorium; that is, a complete hallucination without any recognition of the real world. DT has extreme autonomic hyperactivity (high pulse, blood pressure, and rate of breathing), and 35-60% of patients have a fever. Some patients experience seizures.

Typically the severity of the symptoms experienced will depend on the amount and duration of prior alcohol consumption, as well as the number and severity of previous withdrawals. Even the most severe of these symptoms can occur in as little as 2 hours after cessation; therefore, the overall unpredictability necessitates either pre-planned hospitalization, treatment coordinated with a doctor, or at the very least rapid access to medical care, and a supporting system of friends or family should be introduced prior to addressing detoxification. In many cases, however, symptoms follow a reasonably predictable time frame as exampled below:

Six to 12 hours after the ingestion of the last drink, withdrawal symptoms such as shaking, headache, sweating, anxiety, nausea or vomiting occur. Other comparable symptoms may also exist in this period. Twelve to 24 hours after cessation, the condition may progress to such major symptoms as confusion, hallucinations (with awareness of reality), tremor, agitation, and similar ailments.

At 24 to 48 hours following the last ethanol ingestion, the possibility of seizures should be anticipated. Meanwhile, none of the earlier withdrawal symptoms will have abated. Seizures carry the risk of death for the alcoholic.

Although, most often, the patient's condition begins to improve past the 48-hour mark, it can sometimes continue to increase in severity to delirium tremens, characterized by hallucinations that are indistinguishable from reality, severe confusion, more seizures, high blood pressure and fever which can persist anywhere from 4 to 12 days.

Signs and symptoms of alcohol withdrawal occur primarily in the central nervous system. The severity of withdrawal can vary from mild symptoms such as sleep disturbances and anxiety to severe and life-threatening symptoms such as delirium, hallucinations, and autonomic instability.

Withdrawal usually begins 6 to 24 hours after the last drink. It can last for up to one week. To be classified as alcohol withdrawal syndrome, patients must exhibit at least two of the following symptoms: increased hand tremor, insomnia, nausea or vomiting, transient hallucinations (auditory, visual or tactile), psychomotor agitation, anxiety, tonic-clonic seizures, and autonomic instability.

The severity of symptoms is dictated by a number of factors, the most important of which are degree of alcohol intake, length of time the individual has been using alcohol, and previous history of alcohol withdrawal. Symptoms are also grouped together and classified:

- Alcohol hallucinosis: patients have transient visual, auditory, or tactile hallucinations, but are otherwise clear.

- Withdrawal seizures: seizures occur within 48 hours of alcohol cessations and occur either as a single generalized tonic-clonic seizure or as a brief episode of multiple seizures.

- Delirium tremens: hyperadrenergic state, disorientation, tremors, diaphoresis, impaired attention/consciousness, and visual and auditory hallucinations. This usually occurs 24 to 72 hours after alcohol cessation. Delirium tremens is the most severe form of withdrawal and occurs in 5 to 20% of patients experiencing detoxification and 1/3 of patients experiencing withdrawal seizures.

An opioid overdose is toxicity due to excessive opioids. Examples of opioids include morphine, heroin, fentanyl, tramadol, and methadone. Symptoms include insufficient breathing, small pupils, and unconsciousness. Onset of symptoms depends in part on the route opioids are taken. Among those who initially survive, complications can include rhabdomyolysis, pulmonary edema, compartment syndrome, and permanent brain damage.

Risk factors for opioid overdose include opioid dependence, injecting opioids, using high doses of opioids, mental disorders, and use together with alcohol or benzodiazepines. The risk is particularly high following detoxification. Dependence on prescription opioids can occur from their use to treat chronic pain. Diagnosis is generally based on symptoms.

Initial treatment involves supporting the person's breathing and providing oxygen. Naloxone is then recommended among those who are not breathing. Given naloxone into the nose or as an injection into a muscle appears to be equally effective. Among those who refuse to go to hospital following reversal, the risks of a poor outcome in the short term appear to be low. Efforts to prevent deaths from overdose include improving access to naloxone and treatment for opioid dependence.

Opioid use disorders resulted in 122,000 deaths globally in 2015, up from 18,000 deaths in 1990. In the United States over 33,000 deaths occurred from opioids in 2015, 20,100 from prescription opioids and 13,000 from heroin. Opioid deaths represent more than 60% of all drug overdose related deaths in the United States. The opioid epidemic is believed to be in part due to assurances in the 1990s by the pharmaceutical industry that prescription opioids were safe.

The word "overdose" implies that there is a common safe dosage and usage for the drug; therefore, the term is commonly only applied to drugs, not poisons, though even poisons are harmless at a low enough dosage. Drug overdoses are sometimes caused intentionally to commit suicide, parasuicide or as self-harm, but many drug overdoses are accidental, the result of intentional or unintentional misuse of medication. Intentional misuse leading to overdose can include using prescribed or unprescribed drugs in excessive quantities in an attempt to produce euphoria.

Usage of illicit drugs of unexpected purity, in large quantities, or after a period of drug abstinence can also induce overdose. Cocaine users who inject intravenously can easily overdose accidentally, as the margin between a pleasurable drug sensation and an overdose is small. Unintentional misuse can include errors in dosage caused by failure to read or understand product labels. Accidental overdoses may also be the result of over-prescription, failure to recognize a drug's active ingredient, or unwitting ingestion by children. A common unintentional overdose in young children involves multi-vitamins containing iron. Iron is a component of the hemoglobin molecule in blood, used to transport oxygen to living cells. When taken in small amounts, iron allows the body to replenish hemoglobin, but in large amounts it causes severe pH imbalances in the body. If this overdose is not treated with chelation therapy, it can lead to death or permanent coma. The term 'overdose' is often misused as a descriptor for adverse drug reactions or negative drug interactions due to mixing multiple drugs simultaneously.

Cocaine increases alertness, feelings of well-being, euphoria, energy, competence, sociability, and sexuality. Common side effects include anxiety, increased temperature, paranoia, restlessness, and teeth grinding. With prolonged use, the drug can cause insomnia, anorexia, tachycardia, hallucinations, and paranoid delusions. Possible lethal side effects include rapid heartbeat, abnormal heart rhythms, tremors, convulsions, markedly increased core temperature, renal failure, heart attack, stroke and heart failure.

Depression with suicidal ideation may develop in heavy users. Finally, a loss of vesicular monoamine transporters, neurofilament proteins, and other morphological changes appear to indicate a long-term damage to dopamine neurons. Chronic intranasal usage can degrade the cartilage separating the nostrils (the septum nasi), which can eventually lead to its complete disappearance.

Studies have shown that cocaine usage during pregnancy triggers premature labor and may lead to abruptio placentae.

Include the following:

- Depression

- Shaking

- Feeling unreal

- Appetite loss

- Muscle twitching

- Memory loss

- Motor impairment

- Nausea

- Muscle pains

- Dizziness

- Apparent movement of still objects

- Feeling faint

- Noise sensitivity

- Light sensitivity

- Peculiar taste

- Pins and needles

- Touch sensitivity

- Sore eyes

- Hallucinations

- Smell sensitivity

All sedative-hypnotics, e.g. alcohol, barbiturates, benzodiazepines and the nonbenzodiazepine Z-drugs have a similar mechanism of action, working on the GABA receptor complex and are cross tolerant with each other and also have abuse potential. Use of prescription sedative-hypnotics; for example the nonbenzodiazepine Z-drugs often leads to a relapse back into substance misuse with one author stating this occurs in over a quarter of those who have achieved abstinence.

Delirium tremens (DTs) is a rapid onset of confusion usually caused by withdrawal from alcohol. When it occurs, it is often three days into the withdrawal symptoms and lasts for two to three days. Physical effects may include shaking, shivering, irregular heart rate, and sweating. People may also see or hear things other people do not. Occasionally, a very high body temperature or seizures may result in death. Alcohol is one of the most dangerous drugs from which to withdraw.

Delirium tremens typically only occurs in people with a high intake of alcohol for more than a month. A similar syndrome may occur with benzodiazepine and barbiturate withdrawal. Withdrawal from stimulants such as cocaine does not have major medical complications. In a person with delirium tremens it is important to rule out other associated problems such as electrolyte abnormalities, pancreatitis, and alcoholic hepatitis.

Prevention is by treating withdrawal symptoms. If delirium tremens occurs, aggressive treatment improves outcomes. Treatment in a quiet intensive care unit with sufficient light is often recommended. Benzodiazepines are the medication of choice with diazepam, lorazepam, chlordiazepoxide, and oxazepam all commonly used. They should be given until a person is lightly sleeping. The antipsychotic haloperidol may also be used. The vitamin thiamine is recommended. Mortality without treatment is between 15% and 40%. Currently death occurs in about 1% to 4% of cases.

About half of people with alcoholism will develop withdrawal symptoms upon reducing their use. Of these, three to five percent develop DTs or have seizures. The name delirium tremens was first used in 1813; however, the symptoms were well described since the 1700s. The word "delirium" is Latin for "going off the furrow," a plowing metaphor. It is also called shaking frenzy and Saunders-Sutton syndrome. Nicknames include the shakes, barrel-fever, blue horrors, bottleache, bats, drunken horrors, elephants, gallon distemper, quart mania, and pink spiders, among others.

Benzodiazepine withdrawal syndrome—often abbreviated to benzo withdrawal—is the cluster of symptoms that emerge when a person who has taken benzodiazepines, either medically or recreationally, and has developed a physical dependence undergoes dosage reduction or discontinuation. Development of physical dependence and/or addiction and the resulting withdrawal symptoms, some of which may last for years, may result from either drug-seeking behaviors or from taking the medication as prescribed. Benzodiazepine withdrawal is characterized by sleep disturbance, irritability, increased tension and anxiety, panic attacks, hand tremor, sweating, difficulty with concentration, confusion and cognitive difficulty, memory problems, dry retching and nausea, weight loss, palpitations, headache, muscular pain and stiffness, a host of perceptual changes, hallucinations, seizures, psychosis, and suicide (see "Signs and Symptoms" section below for full list). Further, these symptoms are notable for the manner in which they wax and wane and vary in severity from day to day or week by week instead of steadily decreasing in a straightforward monotonic manner.

It is a potentially serious condition, and is complex and often protracted in time course. Long-term use, defined as daily use for at least three months, is not desirable because of the associated increased risk of dependence, dose escalation, loss of efficacy, increased risk of accidents and falls, particularly for the elderly, as well as cognitive, neurological, and intellectual impairments. Use of short-acting hypnotics, while being effective at initiating sleep, worsen the second half of sleep due to withdrawal effects. Nevertheless, long-term users of benzodiazepines should not be forced to withdraw against their will.

Benzodiazepine withdrawal can be severe and can provoke life-threatening withdrawal symptoms, such as seizures, particularly with abrupt or overly rapid dosage reduction from high doses or long time users. A severe withdrawal response can nevertheless occur despite gradual dose reduction, or from relatively low doses in short time users, even after a single large dose in animal models. A minority of individuals will experience a protracted withdrawal syndrome whose symptoms may persist at a sub-acute level for months, or years after cessation of benzodiazepines. The likelihood of developing a protracted withdrawal syndrome can be minimized by a slow, gradual reduction in dosage.

Chronic exposure to benzodiazepines causes neural adaptations that counteract the drug's effects, leading to tolerance and dependence. Despite taking a constant therapeutic dose, long-term use of benzodiazepines may lead to the emergence of withdrawal-like symptoms, particularly between doses. When the drug is discontinued or the dosage reduced, withdrawal symptoms may appear and remain until the body reverses the physiological adaptations. These rebound symptoms may be identical to the symptoms for which the drug was initially taken, or may be part of discontinuation symptoms. In severe cases, the withdrawal reaction may exacerbate or resemble serious psychiatric and medical conditions, such as mania, schizophrenia, and, especially at high doses, seizure disorders. Failure to recognize discontinuation symptoms can lead to false evidence for the need to take benzodiazepines, which in turn leads to withdrawal failure and reinstatement of benzodiazepines, often to higher doses.

Awareness of the withdrawal reactions, individualized taper strategies according to withdrawal severity, the addition of alternative strategies such as reassurance and referral to benzodiazepine withdrawal support groups, all increase the success rate of withdrawal.

Withdrawal effects caused by sedative-hypnotics discontinuation, such as benzodiazepines, barbiturates, or alcohol, can cause serious medical complications. They are cited to be more hazardous to withdraw from than opioids. Users typically receive little advice and support for discontinuation. Some withdrawal symptoms are identical to the symptoms for which the medication was originally prescribed, and can be acute or protracted in duration. Onset of symptoms from long half-life benzodiazepines might be delayed for up to three weeks, although withdrawal symptoms from short-acting ones often present early, usually within 24–48 hours. There may be no fundamental differences in symptoms from either high or low dose discontinuation, but symptoms tend to be more severe from higher doses.

Daytime reemergence and rebound withdrawal symptoms, sometimes confused with interdose withdrawal, may occur once dependence has set in. 'Reemergence' is the return of symptoms for which the drug was initially prescribed, in contrast, 'rebound' symptoms are a return of the symptoms for which the benzodiazepine was initially taken, but at a more intense level than before; whereas 'interdose withdrawal' is when a prior dosage of drug wears off and beginnings of an entirely new cycle of withdrawal sets in, the symptoms of which dissipate upon taking the next dosage but afterwhich yet another entirely new cycle of withdrawal begins when that dosage wears off, a new onset of withdrawal between each dosage thus called 'interdose withdrawal' and if not properly treated can recur indefinitely in a vicious circle (for which consider a benzo with a long half life (eg. Valium) so the drug does not wear off between doses). Withdrawal symptoms may appear for the first time during dose reduction, and include insomnia, anxiety, distress, weight loss, dizziness, night sweats, shakes, muscle twitches, aphasia, panic attacks, depression, derealization, paranoia, etc., and are more commonly associated with short-acting benzodiazepines discontinuation, like triazolam. Daytime symptoms can occur after a few days to a few weeks of administration of nightly benzodiazepine use or z-drugs such as zopiclone; withdrawal-related insomnia rebounds worse than baseline even when benzodiazepines are used intermittently.

The following symptoms may emerge during gradual or abrupt dosage reduction:

Rapid discontinuation may result in a more serious syndrome

As withdrawal progresses, patients often find their physical and mental health improves with improved mood and improved cognition.

Combined drug intoxication (CDI), also known as multiple drug intake (MDI) or lethal polydrug/polypharmacy intoxication, is an unnatural cause of human death. CDI is often confused with drug overdose, but it is a completely different phenomenon. It is distinct in that it is due to the simultaneous use of multiple drugs, whether the drugs are prescription, over-the-counter, recreational, or some other combination. Alcohol can exacerbate the symptoms and may directly contribute to increased severity of symptoms. The reasons for toxicity vary depending on the mixture of drugs. Usually, most victims die after using two or more drugs in combination that suppress breathing, and the low blood oxygen level causes brain death.

The CDI/MDI phenomenon seems to be becoming more common in recent years. In December 2007, according to Dr. John Mendelson, a pharmacologist at the California Pacific Medical Center Research Institute, deaths by combined drug intoxication were relatively "rare" ("one in several million"), though they appeared then to be "on the rise". In July 2008, the Associated Press and CNN reported on a medical study showing that over two decades, from 1983 to 2004, such deaths have soared. It has also become a prevalent risk for older patients.

Cocaine intoxication refers to the immediate and deleterious effects of cocaine on the body. Although cocaine intoxication and cocaine dependence can be present in the same individual, these syndromes present with different symptoms.

Signs and symptoms of opioid overdose include, but are not limited to:

- Pin-point pupils may occur. Patient presenting with dilated pupils may still be suffering an opioid overdose.

- Decreased heart rate

- Decreased body temperature

- Decreased breathing

- Altered level of consciousness. People may be unresponsive or unconscious.

- Pulmonary edema (fluid accumulation in the lungs)

- Shock

- Death

The peripheral autonomic nervous system, central nervous system and the heart are the main systems that are affected following overdose. Initial or mild symptoms typically develop within 2 hours and include tachycardia, drowsiness, a dry mouth, nausea and vomiting, urinary retention, confusion, agitation, and headache. More severe complications include hypotension, cardiac rhythm disturbances, hallucinations, and seizures. Electrocardiogram (ECG) abnormalities are frequent and a wide variety of cardiac dysrhythmias can occur, the most common being sinus tachycardia and intraventricular conduction delay resulting in prolongation of the QRS complex and the PR/QT intervals. Seizures, cardiac dysrhythmias, and apnea are the most important life-threatening complications.

Barbiturate overdose is poisoning due to excessive doses of barbiturates. Symptoms typically include difficulty thinking, poor coordination, decreased level of consciousness, and a decreased effort to breathe (respiratory depression). Complications of overdose can include noncardiogenic pulmonary edema. If death occurs this is typically due to a lack of breathing.

Barbiturate overdose may occur by accident or purposefully in an attempt to cause death. The toxic effects are additive to those of alcohol and benzodiazepines. The lethal dose varies with a person's tolerance and how the drug is taken. The effects of barbiturates occur via the GABA neurotransmitter. Exposure may be verified by testing the urine or blood.

Treatment involves supporting a person's breathing and blood pressure. While there is no antidote, activated charcoal may be useful. Multiple doses of charcoal may be required. Hemodialysis may occasionally be considered. Urine alkalinisation has not been found to be useful. While once a common cause of overdose, barbiturates are now a rare cause.

The signs and symptoms of benzodiazepine dependence include feeling unable to cope without the drug, unsuccessful

attempts to cut down or stop benzodiazepine use, tolerance to the effects of benzodiazepines, and withdrawal symptoms when not taking the drug. Some withdrawal symptoms that may appear include anxiety, depressed mood, depersonalisation, derealisation, sleep disturbance, hypersensitivity to touch and pain, tremor, shakiness, muscular aches, pains, twitches, and headache. Benzodiazepine dependence and withdrawal have been associated with suicide and self-harming behaviors, especially in young people. The Department of Health substance misuse guidelines recommend monitoring for mood disorder in those dependent on or withdrawing from benzodiazepines.

Benzodiazepine dependence is a frequent complication for those prescribed for or using for longer than four weeks, with physical dependence and withdrawal symptoms being the most common problem, but also occasionally drug-seeking behavior. Withdrawal symptoms include anxiety, perceptual disturbances, distortion of all the senses, dysphoria, and, in rare cases, psychosis and epileptic seizures.

People who engage in polypharmacy and other hypochondriac behaviors are at an elevated risk of death from CDI. Elderly people are at the highest risk of CDI, because of having many age-related health problems requiring many medications combined with age-impaired judgment, leading to confusion in taking medications.

A withdrawal syndrome, also called a discontinuation syndrome is a set of symptoms occurring in discontinuation or dosage reduction of some types of medications. The risk of a discontinuation syndrome occurring increases with dosage and length of use.

- Alcohol withdrawal syndrome, symptoms seen when an individual reduces or stops alcohol consumption after periods of excessive alcohol intake

- Antidepressant discontinuation syndrome, a syndrome that can occur following the interruption, dose reduction, or discontinuation of SSRI or SNRI medications

- Antipsychotic withdrawal syndrome or dopamine supersensitivity psychosis, symptoms seen when an individual reduces or suddenly stops antipsychotics

- Benzodiazepine withdrawal syndrome, symptoms that appear when a long term user stops taking benzodiazepines or reduces the dosage

- Cannabis withdrawal, a form of withdrawal associated with the substance cannabis

- Drug withdrawal

- Neonatal withdrawal, a withdrawal syndrome of infants, caused by administration of drugs or the prenatal exposure to a substance

- Nicotine withdrawal, the effects felt by a person who is nicotine dependent and suddenly stops or significantly reduces his or her nicotine intake

- Opioid withdrawal, symptoms seen cessation or rapid reduction of intake of opioid class drugs

Signs and symptoms of opioid intoxication include:

- Decreased perception of pain

- Euphoria

- Confusion

- Desire to sleep

- Nausea

- Constipation

- Miosis

The symptoms of a hallucinogenic toxidrome include disorientation, hallucinations, hyperactive bowel sounds, panic, and seizures. Complications include hypertension, tachycardia, and tachypnea. Substances that may cause this toxidrome include substituted amphetamines, cocaine, and phencyclidine.

The symptoms of a cholinergic toxidrome include bronchorrhea, confusion, defecation, diaphoresis, diarrhea, emesis, lacrimation, miosis, muscle fasciculations, salivation, seizures, urination, and weakness. Complications include bradycardia, hypothermia, and tachypnea. Substances that may cause this toxidrome include carbamates, mushrooms, and organophosphates.

Common mnemonics for organophosphate poisoning include the "killer B's" of bradycardia, bronchorrhea and bronchospasm because they are the leading cause of death, and SLUDGE - Salivation, Lacrimation, Urination, Diarrhea, Gastrointestinal distress, and Emesis.

An alternative mnemonic is DUMBBELLSS - Diarrhea, Urination, Miosis, Bradycardia, Bronchospasm, Emesis, Lacrimation, Lethargy, Salivation and Seizures.