Summary of interations between anti-HIV medicines and recreational drugs

Drug	Interaction	Significance	Recommendation
Alcohol	None	None	None
Amphetamines	Possible prolonged effect or higher concentrations with ARVS especially ritonavir	High body temperature, high blood pressure, fast heartbeat, rapid breathing, seizures	Avoid using with ritonavir if possible – or use less
Benzodiazepines	Norvir may increase levels	Over-sedation, respiratory depression	Lower benzodiazepine dose if necessary
Cannabis	None	None	None
Cocaine	None	None	None
Ecstasy, MDMA	Possible higher concentrations with ritonavir, other PIs and efavirenz	1 death reported – low sodium level in the blood, abnormal heartbeat, fast heartbeat, high body temperature, sweating, seizures, overactive reflexes, tremors, disintegration of muscle fibres.	Avoid using with ritonavir if possible – or use less – stay hydrated and avoid alcohol.
GHB	Possible interaction with ritonavir	1 case of near-fatal GHB poisoning with ritonavir + saquinavir – muscle spasms, seizures, slow heart rate, poor breathing, unconsciousness	Caution with ritonavir, other PIs, efavirenz – be aware of signs of GHB toxicity.
Heroin, buprenorphine and methadone	Efavirenz and nevirapine: methadone level up to 60% lower.Efavirenz: buprenorphine levels up to 50% lower. Ritonavir: may increase or decrease opiate level. Nelfinavir and Kaletra: reduces level of methadone. Methadone: decreases level of d4T and ddI, doubles level of AZT. Heroin: may be processed faster with PIs and efavirenz.	Lower levels of methadone and heroin may lead to signs of withdrawal. Higher levels of ARVs may increase side effects.	Higher dose of methadone may be needed. Use half the normal dose of AZT. No recommendation for d4T or ddI. Buprenorphine dose not usually changed.
Ketamine	Possible higher concentrations with ritonavir, nelfinavir and efavirenz	Poor breathing, unconsciousness, hallucinations	Caution with ritonavir, other PIs, efavirenz – be aware of signs of ketamine toxicity.
LSD	Possible higher concentrations	Hallucinations, agitation, psychosis, flashbacks	Caution with ritonavir, other PIs, efavirenz – be aware of signs of LSD toxicity.
PCP (angel dust)	Possible higher concentrations	High body temperature, high blood pressure, seizures, disintegration of muscle fibres.	Caution with ritonavir, other PIs, efavirenz – be aware of signs of PCP toxicity.
Sildenafil (Viagra) and similar drugs	Ritonavir increases level of erectile dysfunction agents	Headache, priapism, palpitations, visual changes, low blood pressure.	Use less (eg 25mg instead of 100mg sildenafil)

Drug

Interaction

Significance

Recommendation

Alcohol

None

Amphetamines

Possible prolonged effect or higher concentrations with ARVS especially ritonavir

High body temperature, high blood pressure, fast heartbeat, rapid breathing, seizures

Avoid using with ritonavir if possible – or use less

Benzodiazepines

Norvir may increase levels

Over-sedation, respiratory depression

Lower benzodiazepine dose if necessary

Cannabis

None

Cocaine

None

Ecstasy, MDMA

Possible higher concentrations with ritonavir, other PIs and efavirenz

1 death reported – low sodium level in the blood, abnormal heartbeat, fast heartbeat, high body temperature, sweating, seizures, overactive reflexes, tremors, disintegration of muscle fibres.

Avoid using with ritonavir if possible – or use less – stay hydrated and avoid alcohol.

GHB

Possible interaction with ritonavir

1 case of near-fatal GHB poisoning with ritonavir + saquinavir – muscle spasms, seizures, slow heart rate, poor breathing, unconsciousness

Caution with ritonavir, other PIs, efavirenz – be aware of signs of GHB toxicity.

Heroin, buprenorphine and methadone

Efavirenz and nevirapine: methadone level up to 60% lower.Efavirenz: buprenorphine levels up to 50% lower. Ritonavir: may increase or decrease opiate level. Nelfinavir and Kaletra: reduces level of methadone. Methadone: decreases level of d4T and ddI, doubles level of AZT. Heroin: may be processed faster with PIs and efavirenz.

Lower levels of methadone and heroin may lead to signs of withdrawal. Higher levels of ARVs may increase side effects.

Higher dose of methadone may be needed. Use half the normal dose of AZT. No recommendation for d4T or ddI. Buprenorphine dose not usually changed.

Ketamine

Possible higher concentrations with ritonavir, nelfinavir and efavirenz

Poor breathing, unconsciousness, hallucinations

Caution with ritonavir, other PIs, efavirenz – be aware of signs of ketamine toxicity.

LSD

Possible higher concentrations

Hallucinations, agitation, psychosis, flashbacks

Caution with ritonavir, other PIs, efavirenz – be aware of signs of LSD toxicity.

PCP (angel dust)

Possible higher concentrations

High body temperature, high blood pressure, seizures, disintegration of muscle fibres.

Caution with ritonavir, other PIs, efavirenz – be aware of signs of PCP toxicity.

Sildenafil (Viagra) and similar drugs

Ritonavir increases level of erectile dysfunction agents

Headache, priapism, palpitations, visual changes, low blood pressure.

Use less (eg 25mg instead of 100mg sildenafil)

Table based on: T Auntonio and A Lin-in Tseng. Interactions Between Recreational Drugs and Anti-retroviral Agents, Annals of Pharmacotherapy. 2000, October, Volume 36.