Antiretroviral agents causing

WARNING Rarely causes allergy never rechallenge Uses w/ antiretroviral agents for HIV-1 Infxn in Tx-experienced pts w/ evidence of viral replication despite ongoing antiretroviral therapy Action Viral fusion inhibitor Dose 90 mg... 

The oral bioavailability of stavudine in adults is 86%. Food does not interfere with its absorption. Peak plasma concentrations are reached within lh. The renal elimination accounts for 40% of its clearance. In addition to glomerular filtration, it undergoes active tubular secretion. Sixty percent of the remaining drug is eliminated by endogenous pathways. Its binding to plasma proteins is less than 5%. Stavudine in combination with other antiretroviral agents is indicated for the treatment of HIV-1 infection. It causes suppression of HIV and sustained increase in CD4+ cells. 

In combination with other antiretroviral agents, stavudine has caused fatal lactic acidosis in some patients. It is also associated with motor weakness in which case it should be discontinued. Peripheral neuropathy is the most common toxicity associated with stavudine, which is more prevalent at high doses (4mg/kg per day). Neuropathy in these patients generally is associated with numbness, tingling or pain in feet or hands. Patients treated with the combination of stavudine and didanosine may also exhibit liver function abnormalities (hepatic steatosis) and pancreatitis. It may also be associated with the etiology of HIV lipodystrophy syndrome. 

Highly Active Antiretroviral Therapy (HAART) HAART slows or inhibits reverse transcriptase and protease enzymes by using several antiretroviral agents. HAART decreases the viral load. The viral load measures the amount of virus in the body. A decreased viral load causes an increase in CD4+ T cells and results in the immune system being able to identify, neutralize, and destroy non-self-cells. HAART therapy must be adhered to because the virus can become resistant to the antiretroviral agents. The patient must also adhere to nutritional therapy and avoid infections. 

Protease inhibitors, which are the most potent antiretroviral agents currently available, were the end result of coordinated chemical design and structure-based computational analysis of the protease enzyme. With identification of the protease crystalline structure and identification of active binding sites, scientists were able to create compounds that would fit the protease enzyme with strong affinity and cause an inhibition of protease function. The clinical impact of these man-made drugs is... 

Pseudoallergic reactions resemble allergic reactions clinically but are not immunologically mediated. Examples include asthma and rashes caused by aspirin and maculopapular erythematous rashes due to ampicillin or amoxicillin in the absence of penicillin hypersensitivity. Few other entities that can initiate this reaction are sulfonamides, anticonvulsants (phenytoin, carbamazepine and phenobarbital), NSAIDs (aspirin, naproxen, nabumetone and keto-profen), antiretroviral agents and cephalosporins [1 ]. 

D/C antiretrovirals D/C all hepatotoxic agents rule out other causes do not rechallenge with NVP... 

D/C all antiretrovirals as well as any other possible cause aggressive symptom support do not rechallenge patient with offending agent if caused by NVP, avoid NNRTI class, if possible... 

Drug interactions The extent to which vitamin D supplementation alters drug effectiveness and toxicity in humans has been systematically reviewed. Bile acid sequestrants and lipase inhibitors were found to inhibit the absorption of vitamin D from the gut. Statins, rifampicin, isoniazid, hydroxychloroquine, antiepileptics, corticosteroids, immimo-suppressive and chemotherapeutic agents, antiretroviral drugs and H2 receptor antagonists interfered with vitamin D metabolism. The interaction between vitamin D and thiazide diuretics could result in hypercalcaetnia. Vitamin D supplementation decreases concentrations of atorvastatin, and could cause hypercalcaetnia in elderly individuals or tixose with compromised renal function or hyperparathyroidism [84 ]. 

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