disulfiram + ritonavir

This entry describes the potential drug interaction between disulfiram and ritonavir when coadministered. The primary concern with this combination is the potential for a disulfiram-like reaction due to the alcohol content present in certain ritonavir formulations. Ritonavir oral solution contains 43% alcohol (v/v), while ritonavir capsules contain 12% alcohol (w/w). Ritonavir tablets do not contain alcohol. Disulfiram inhibits aldehyde dehydrogenase (ALDH), preventing the breakdown of alcohol and leading to a buildup of acetaldehyde. When alcohol is present, this causes unpleasant symptoms such as flushing, weakness, nausea, tachycardia, hypotension, respiratory difficulties, headaches, dizziness, sweating, and chest pain. **Clinical Recommendations:** - Coadministration of disulfiram with ritonavir oral solution is not recommended. - The use of ritonavir capsules, ritonavir oral solution, or lopinavir-ritonavir oral solution with disulfiram should be avoided. - Ritonavir tablets, which are alcohol-free, may be a safer alternative when disulfiram therapy is required. **Interaction Effects:** - Efavirenz has been shown to potentially enhance disulfiram's effectiveness by increasing its inhibition of ALDH activity. - Atazanavir has been shown to reduce the effect of disulfiram on ALDH activity, potentially rendering it ineffective. - Disulfiram does not appear to significantly affect the studied antiretroviral medications. This interaction is particularly relevant for HIV-infected individuals with alcohol use disorders. While disulfiram is infrequently used in this population, proper monitoring could allow its use for alcohol and potentially cocaine use disorders.