Cocaine
Cocaine is a central nervous system stimulant that increases dopamine, noradrenaline, and serotonin. It carries important cardiovascular risks and may interact dangerously with erection medicines, antidepressants, and other stimulants.
What is it?
Cocaine is a central nervous system stimulant that increases the availability of dopamine, noradrenaline, and serotonin in the brain. It may appear as powder (cocaine hydrochloride), freebase paste, crack (smoked form), or other forms.
The purity and concentration of available products vary a lot, which significantly increases risk.
How is it used?
| Route | Onset | Duration | Notes |
|---|---|---|---|
| Snorted / inhaled | Seconds | 20-30 min | Most common; may damage the nasal lining |
| Smoked (crack/freebase) | Seconds | 5-15 min | Faster and more intense, but shorter |
| Injected | Seconds | 20-60 min | Very intense effect; greater risk of complications and infections |
| Oral | 20-30 min | Up to 90 min | Less common; slower onset |
Total effects may last between 20 and 90 minutes depending on dose, route, and the person.
How does it work?
Cocaine blocks the reuptake of dopamine, noradrenaline, and serotonin, increasing their concentration at synapses. It can produce:
- Intense euphoria and a sense of well-being
- Increased energy, confidence, and alertness
- Faster heart rate and increased blood pressure
- Central nervous system stimulation
- Reduced appetite and reduced need for sleep
Effects wear off quickly, which may lead to compulsive redosing.
Specific risks
1. Cardiovascular problems
Cocaine significantly raises blood pressure and heart rate. It may cause:
- Chest pain
- Cardiac arrhythmias
- Heart attack
- Stroke
Risk increases with high doses, frequent redosing, and mixing with other substances.
2. Overstimulation and anxiety
- Intense anxiety, paranoia, panic attacks
- Tremors, muscle tension, sweating
- Increased body temperature
- It may trigger psychosis, hallucinations, or persecutory thoughts
3. Redosing
Effects drop quickly and may lead to compulsive repeated dosing. It is recommended to wait at least 60-90 minutes before redosing. Risks include overdose, heart problems, anxiety, and paranoia.
4. Body temperature and dehydration
Cocaine raises body temperature and may cause heat stroke, dehydration, cramps, and muscle damage (rhabdomyolysis). This risk is higher in hot environments and during long sessions.
5. Exhaustion and post-use depression
After the effects fade, intense tiredness, sadness, irritability, and a strong urge to use again (“crash”) are common. This period may increase the risk of problematic use.
Interactions with medicines
| Medicine | Risk level | Effect and recommended action |
|---|---|---|
| Sildenafil / tadalafil / vardenafil (erection medicines) | Very high | Dangerous rise in blood pressure; risk of heart attack, arrhythmias, and stroke. Do NOT combine. Avoid 24-48h before and after. |
| SSRI antidepressants | Moderate | Greater risk of anxiety, agitation, and serotonin syndrome. Use caution. Do not combine without professional guidance. |
| MAOI antidepressants | Very high | Very high risk of severe hypertension and hypertensive crisis. Do NOT combine. Contraindicated. |
| Stimulants (methylphenidate, amphetamines, modafinil) | Very high | Extreme overstimulation, tachycardia, arrhythmias, psychosis, severe hypertension. Do NOT combine. |
| Alcohol | Moderate | Higher risk of dehydration, liver damage, and impulsive behaviour. Avoid combining. |
| Benzodiazepines | Moderate | May mask anxiety, but the mix may increase the risk of respiratory depression and overdose. Do not combine without medical supervision. |
| Antipsychotics | Moderate | May lower seizure threshold and increase neurological side effects. Consult a healthcare professional. |
Interactions with antiretrovirals
Direct interactions between cocaine and antiretrovirals are less well documented than with some other substances. The main indirect risk is that both may add strain to the cardiovascular system and the liver. Telling your healthcare team allows appropriate monitoring.
Harm reduction
- Use the smallest amount possible as infrequently as possible
- Avoid constant redosing: wait at least 60-90 minutes
- Hydrate and rest regularly
- Do not combine with alcohol or erection medicines (sildenafil, tadalafil, vardenafil)
- Do not use alone: have a trusted person nearby
- Take care of your mental health: if anxiety or paranoia are frequent, seek support
- If you have heart problems, hypertension, or pre-existing anxiety, talk with a healthcare professional before using
- Maintain ART adherence and tell your healthcare team about use
Warning signs
- Chest pain or pressure
- Palpitations or irregular heartbeat
- Shortness of breath or trouble breathing
- Intense anxiety, paranoia, or hallucinations
- Very high body temperature or excessive sweating
- Confusion, seizures, or loss of consciousness
If any of these happen, seek medical care immediately.
When should you seek medical care?
- Chest pain or trouble breathing
- Seizures or loss of consciousness
- Very high or persistently irregular heart rate
- Very high body temperature that does not come down
- Anxiety or paranoia that does not improve
What does the evidence say?
Interactions between cocaine and erection medicines (PDE5 inhibitors) are well documented and are a serious contraindication. The combination may lead to severe hypotension, arrhythmias, or heart attack. Interactions with antidepressants, especially MAOIs, are also documented as high risk. Direct interactions with specific antiretrovirals require more research, but the shared cardiovascular and liver burden justifies caution and open communication with the healthcare team.