Kaletra and Proloprim

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

The following interaction applies only if you are taking ritonavir products (e.G., Norvir, Kaletra) in a solution formulation: Ritonavir-containing oral solutions are formulated with alcohol. In rare cases, trimethoprim may affect the breakdown of alcohol leading to what is termed a "disulfiram reaction." This condition produces unpleasant side effects such as flushing, throbbing in head and neck, throbbing headache, difficulty breathing, nausea, vomiting, sweating, thirst, chest pain, fast or pounding heartbeats, low blood pressure, dizziness, lightheadedness, blurred vision, and confusion. Let your doctor know if you experience any of these symptoms. More severe reactions may include heart attack, heart failure, unconsciousness, and convulsions. It is best to avoid drinking alcohol while you are being treated with trimethoprim. Check your food and medicine labels to be sure those products do not contain alcohol. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

MONITOR: A disulfiram-like reaction has been reported in two patients who consumed alcohol while taking sulfamethoxazole-trimethoprim DS every 12 hours, although a causal relationship has not been established. The mechanism of interaction is unknown. Both ritonavir oral solution and lopinavir-ritonavir oral solution contain a substantial amount of alcohol (greater than 40% by volume), which, theoretically, can produce a disulfiram-like reaction when coadministered with sulfamethoxazole-trimethoprim. Pharmacokinetically, coadministration of ritonavir (500 mg every 12 hours) and sulfamethoxazole-trimethoprim (single 800mg-160 mg dose) has resulted in a 20% decrease in the area under the plasma concentration-time curve (AUC) of sulfamethoxazole and a 20% increase in the AUC of trimethoprim. The plasma level of ritonavir was not affected. These alterations are unlikely to be of clinical significance, thus dosage adjustments should not be necessary.

MANAGEMENT: Until further information is available, it may be advisable to avoid using ritonavir oral solution and lopinavir-ritonavir oral solution with sulfamethoxazole-trimethoprim. Patients who are prescribed the combination should be alerted to the potential of a disulfiram reaction, which may include symptoms such as flushing, throbbing in head and neck, throbbing headache, respiratory difficulty, nausea, vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, tachycardia, hypotension, syncope, weakness, vertigo, blurred vision, and confusion.

Kaletra

Generic Name: lopinavir / ritonavir

Brand name: Kaletra

Synonyms: n.a.

What is Kaletra?

Proloprim

Generic Name: trimethoprim

Brand name: Proloprim, Primsol, Trimpex

Synonyms: n.a.

What is Proloprim?