Case 17 – A 29-year-old woman with substance dependence

A 26-year-old G7P3 woman at 34 weeks’ gestation presents to the emergency department because she feels she is beginning to experience contractions and does not have an obstetrician to consult. On examination her pupils are dilated and she appears agitated and nervous. She then changes her mind and says she does not want further evaluation because it has been too long since her last “smoke.” She is adamant about needing to leave right away. Upon further questioning, she states that if she does not get to smoke soon, she will become very sleepy and depressed, and will have intense food cravings. She has been in inpatient drug rehabilitation twice but always relapses back to her drug of choice. She is currently living at a halfway house, is on welfare, and does not have custody of any of her 3 children. “They will probably take this one away from me, too,” she adds as she begins to cry. She says she used to be able to get high for $10 per day, but now it costs up to $100 per day. She affords her habit by trading drugs and money for sex; she has not been tested for HIV or other sexually transmitted diseases in recent memory.

What is the most likely diagnosis?

Cocaine dependence. This patient exhibits the classic signs of addiction: she has tolerance for the drug (requires more to achieve the same effect), and experiences withdrawal symptoms without it. She has continued to use cocaine despite the negative consequences it brings, and she has been unable to bring herself to stop using despite many attempts. Smoking cocaine results in feelings of euphoria and heightened energy, while depression, hunger, and sleepiness are symptoms of withdrawal. The criteria for substance dependence can be remembered using the mnemonic WITHDrawIT:

1. Withdrawal
2. Interest or important activities given up or reduced
3. Tolerance
4. Harm (physical and psychosocial) with continued use
5. Desire to cut down or control use
6. Intended time/amount of use exceeded
7. Time spent obtaining/using the substance is increased

What behavioral changes are associated with cocaine use?

Behavioral changes may include:

1. Blunting of feelings
2. Decreased appetite
3. Euphoria and increased energy
4. Heightened anxiety, irritability, or anger
5. Hypervigilance and heightened alertness
6. Impaired judgment
7. Increase in sexual excitement and spontaneous ejaculation
8. Increased risk for psychosis
9. Increased self-confidence
10. Interpersonal sensitivity

What physical changes are associated with cocaine use?

Physical changes may include:

1. Chest pain and/or arrhythmias due to vasospasm in coronary arteries
2. Confusion, seizures, stupor, or coma
3. Diaphoresis or chills
4. Dilated pupils
5. Increased pulse and blood pressure due to vasoconstriction
6. Muscle weakness, dystonia, or dyskinesia
7. Nausea or vomiting
8. Psychomotor slowing or agitation
9. Respiratory depression
10. Weight loss

What are the risks of cocaine use to the patient’s unborn child?

Since cocaine readily crosses the placenta and is metabolized slowly in fetuses, they can be exposed to significant levels of cocaine for long periods. Because of its vasoconstrictive properties, cocaine use increases the risk of fetal hypoxia and abruptio placentae.
In humans the most common consequences of cocaine abuse during pregnancy include premature birth, lower birth weight, respiratory distress, bowel infarctions, cerebral infarctions, reduced head circumference, and increased risk of seizures. Behaviorally, these newborns show an increased degree of tremulousness, crying, and irritability, and are overreactive to environmental stimuli. Within a month of birth these behaviors recover dramatically, but never to normal levels. It is important to remember that cocaine can be found in breast milk up to 60 hours after the last use.

By Kristen Vierregger, University of Pennsylvania School of Medicine, Class of 2008; in association with Le TT, Schabelman E, Shivaram A, and Klein J, eds: First Aid Cases for the USMLE Step 2 CK. New York: McGraw-Hill, 2007.