Substance-Related Disorders: Opioids

SOURCE

Source: Doering PL, Li RM. Substance-related disorders I: overview and depressants, stimulants, and hallucinogens. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861&sectionid=146064131. Accessed April 12, 2017.

DEFINITION

• Addiction characterized by behaviors that include:

  • Chronicity.

  • Impaired control over drug use.

  • Compulsive use.

  • Continued use despite harm.

  • Craving.

• Physical dependence: state of adaptation manifested by withdrawal syndrome following:

  • Cessation.

  • Rapid dose reduction.

  • Decreasing blood levels.

  • Administration of antagonist.

• Withdrawal: development of substance-specific syndrome following cessation or reduced intake of substance that had been used regularly.

PATHOPHYSIOLOGY

• Complications of heroin use include:

  • Overdoses.

  • Anaphylactic reactions to impurities.

  • Nephrotic syndrome.

  • Septicemia.

  • Endocarditis.

  • Acquired immunodeficiency.

• Opioids are commonly combined with stimulants (eg, cocaine [speedball]) or alcohol).

• Peak respiratory depressant effects occur later and last longer than peak analgesic effects.

EPIDEMIOLOGY

• Number of people aged 12 and older who used prescription pain relievers illicitly doubled from 2.6 to 5.2 million from 1999 to 2006.

• In 2006, 5.2 million people surveyed used prescription pain relievers illicitly in past month, 17 times number of people who used heroin.

• Majority of illicitly used prescription opioids obtained from physicians rather than drug dealers.

CLINICAL PRESENTATION

SIGNS AND SYMPTOMS

• Opioid intoxication:

  • Euphoria.

  • Dysphoria.

  • Apathy.

  • Sedation.

  • Attention impairment.

• Opioid withdrawal:

  • Lacrimation.

  • Rhinorrhea.

  • Mydriasis.

  • Piloerection.

  • Diaphoresis.

  • Diarrhea.

  • Yawning.

  • Fever.

  • Insomnia.

  • Muscle aches.

• Heroin withdrawal begins within a few hours after stopping drug and reaches peak within 36–72 hours.

• Methadone withdrawal may not begin for several days and peak reached at ~72 hours.

• Duration of withdrawal ranges from 3–14 days.

DIAGNOSIS

LABORATORY TESTS

• Opioid use and dependence: Urine drug screen.

  • When toxicology screens necessary, collect urine immediately when patient presents for treatment.

• Withdrawal: Serum electrolytes, complete blood count (CBC)

DIFFERENTIAL DIAGNOSIS

• Dependence:

  • Other drug dependence (alcohol, amphetamines)

  • Underlying psychiatric illness (depression, personality disorder)

• Withdrawal:

  • Other drug withdrawal (alcohol, benzodiazepines, amphetamines, cocaine)

  • Nausea or vomiting due to other causes (influenza or other viral syndrome)

  • Delirium suggests withdrawal from another drug (eg, alcohol).

DESIRED OUTCOMES

• Cessation of use of drug.

• Termination of drug-seeking behaviors.

• Return to normal functioning.

• Goals of treatment for withdrawal.

  • Prevent progression of withdrawal to life-threatening severity.

  • Enable patient participation in treatment program.

TREATMENT: NONPHARMACOLOGIC THERAPY

• Support vital functions as required.

TREATMENT: OPIOID INTOXICATION

• Naloxone.

  • Give 0.4–2 mg IV every 3 min for acute opioid overdoses.

  • Treatment may revive unconscious patients with respiratory depression but ...