1. 
   

   Is this patient intoxicated with marijuana?

   
   
2. 
   

   Does marijuana cause withdrawal?

   
   
3. 
   

   How is hallucinogen intoxication managed?

   
   
4. 
   

   How is gamma-hydroxybutyrate (GHB) overdose treated?

   
   
5. 
   

   What medical problems are caused by inhalants?

Patients may be admitted to a hospital with an overdose, intoxication, or withdrawal syndrome from drugs of abuse. More commonly, patients admitted with medical problems or trauma may be abusing illicit drugs and may develop complications of this during their inpatient stay. It is important to ask all patients about drug use. Recognition of problems due to drug abuse can help clinicians provide optimal care to hospitalized patients.

There are many different drugs that may be abused. In the hospital setting, certain classes of drugs of abuse are more likely to be encountered due to the high prevalence of use outside a hospital setting or due to medical consequences of use. Alcohol abuse is widely prevalent and encountered in hospital settings due to intoxication or withdrawal. Cocaine use may result in exacerbation of angina or asthma. Other drug classes are encountered less frequently in hospital settings due to lower prevalence of overall use, as well as lower incidence of severe medical complications. It is worthwhile for practitioners to be aware of these complications, which are often related to acute intoxication but may also be due to withdrawal. This chapter covers adverse effects of marijuana, hallucinogens, other “club drugs” such as gamma-hydroxybutyrate (GHB), and inhalants.

Hospitalized patients will frequently be using more than a single drug. Polysubstance abuse is the norm, rather than the exception. Patients diagnosed with one substance use disorder (SUD) will often have another SUD. For example, nearly all patients with hallucinogen dependence also abuse alcohol. It is important to ask patients directly about all illicit drug use. Many patients are forthcoming with medical personnel if they are asked in a nonjudgmental manner. Other clues from a thorough physical examination and some common laboratory tests can help establish a diagnosis of recent drug use (Table 236-1).

Some patients are able to use illicit substances while hospitalized. They may bring drugs and possibly paraphernalia with them at admission (in clothing, a purse, or other possessions), or visitors may bring drugs to a patient sometime during the hospitalization. Occasionally a patient may obtain drugs from another patient or from hospital personnel. Under these circumstances, intoxication may present with altered mental status, unexpected resolution of withdrawal symptoms, or a change in patient behavior. Drug use during a hospital stay may be verified by urine drug testing, especially confirmatory testing for specific substances that have not been prescribed. Hospital security personnel may be able to search the patient’s hospital room and possibly inspect the patient’s belongings. The hospital’s risk management department should be notified of any illicit drug use on the premises by a patient. Depending on the situation, discovery of this drug use need not result in a drastic response such as immediate discharge of the patient. It may be used as an opportunity for brief intervention to address the seriousness of the patient’s addiction.

Marijuana is the most frequently abused drug in the United States, with a prevalence of around 4% of the adult population that uses regularly. This rate has remained relatively steady since the early 1990s. Marijuana is also known as cannabis, “pot,” “weed,” “hash,” and many other names.

Is This Patient Intoxicated with Marijuana?

The onset of acute marijuana intoxication is within minutes when smoked, and the effects last for 3 to 4 hours. Acute psychological signs of intoxication include euphoria, time distortion, and short-term memory impairment. Acute physiological signs of intoxication include elevation in heart rate, blood pressure, and respiratory rate, as well as dry mouth and conjunctival injection (bloodshot eyes). Other effects are an increase in appetite (“the munchies”) and impairment in reaction time. Impairment of concentration and motor performance lasts for 12 to 24 hours due to accumulation of marijuana in adipose tissue, with slow release of tetrahydrocannabinol from fatty tissue stores and enterohepatic recirculation. Thus marijuana users may think that they are no longer impaired several hours after use when the acute mood-altering effects wear off. However, impairment of cognition, coordination, and judgment lasts much longer than the subjective feeling of being “high.” Impairment is intensified by combination with other drugs, especially alcohol. This explains why fatal traffic accidents occur more often among individuals who test positive for marijuana, and industrial accidents are also more likely.

The differential diagnosis of marijuana intoxication includes intoxication with other drugs of abuse. Marijuana intoxication appears clinically similar to sedative intoxication, but marijuana intoxication may have more psychotic features and is differentiated by elevated vital signs instead of vital sign depression. On physical examination, conjunctival injection is a clue to determine marijuana intoxication.

Acute intoxication with marijuana alone rarely requires medical treatment, although dysphoria may result in distress that causes the user to seek help. First-time users, older persons, users of high-potency marijuana, or those predisposed to psychiatric illness are at higher risk of experiencing unpleasant effects during intoxication. These unpleasant effects, such as anxiety, paranoia, or palpitations, are managed with supportive treatment (Table 236-2). Placing the distraught user in a quiet environment and maintaining gentle contact is often sufficient until the acute effects subside. More severe marijuana effects such as paranoia or psychosis with hallucinations may result in extreme anxiety or agitation. This requires close observation with possible administration of a benzodiazepine or haloperidol for sedation.

Patients with medical comorbidities are at higher risk for adverse outcomes from marijuana intoxication. Patients with coronary artery disease may develop angina from tachycardia caused by marijuana. Immunosuppressed patients are at higher risk for infections, especially pulmonary aspergillosis from spores found in marijuana preparations. Particulate matter from unfiltered marijuana cigarettes (“joints” or “blunts”) may trigger an exacerbation of asthma or chronic obstructive pulmonary disease.

Does Marijuana Cause Withdrawal?

Heavy marijuana use for more than 3 weeks results in a withdrawal syndrome after abrupt cessation. Marijuana withdrawal begins within 10 hours of the last dose and consists of irritability, agitation, depression, insomnia, nausea, anorexia, and tremor. Most symptoms peak in 48 hours and last for 5 to 7 days. Some symptoms, such as unusual dreams and irritability, can persist for weeks. The differential diagnosis for marijuana withdrawal syndrome includes major depression and viral gastroenteritis. Major depression lasts longer than the expected timeframe for resolution of marijuana withdrawal, and a viral syndrome is accompanied by fever and other changes in vital signs not seen with marijuana withdrawal. Marijuana withdrawal is uncomfortable but not life threatening. Thus treatment is entirely supportive and nearly always accomplished without the need for adjunctive medications.