Acyclovir adverse effects

An in vitro and in vivo study showed a drug interaction between penicillin and acyclovir by means of inhibition of OATl and OATS transporters, subsequently decreasing the renal excretion of acyclovir. Patients should be monitored closely for acyclovir adverse effects when given in combination with penicillin [45 ]. 

The adverse effects of valacyclovir and acyclovir are similar. Toxicity is generally minimal, consisting largely of headache, nausea, and diarrhea. Less frequently observed are skin rash, fatigue, fever, hair loss, and depression. Reversible renal dysfunction (azotemia) and neurotoxicity (tremor, seizure, delirium) are dose-Umiting toxicides of intravenous acyclovir. Adequate hydration and slow drug infusion can minimize the risk of renal toxicity. 

For each patient, select the drug that most likely caused the adverse effect Acyclovir Amantadine Dideoxycytldlne Foscarnet Ganciclovir Idoxuridine... 

Gastrointestinal complaints (eg, nausea, diarrhea, vomiting, flatulence) are the most common adverse effects but rarely require discontinuation of therapy. Other potential adverse effects include headache and asthenia. Tenofbvir-associated proximal renal tubulopathy causes excessive renal phosphate and calcium losses and 1-hydroxylation defects of vitamin D, and preclinical studies in several animal species have demonstrated bone toxicity (eg, osteomalacia). Monitoring of bone mineral density should be considered with long-term use in those with risk factors for or with known osteoporosis, as well as in children. Reduction of renal function over time, as well as cases of acute renal failure and Fanconi s syndrome, have been reported in patients receiving tenofovir alone or in combination with emtricitabine. For this reason, tenofovir should be used with caution in patients at risk for renal dysfunction. Tenofovir may compete with other drugs that are actively secreted by the kidneys, such as cidofovir, acyclovir, and ganciclovir. 

Adverse Effects. Topical application of acyclovir may produce local irritation of cutaneous and mucosal tissues. Prolonged systemic administration of acyclovir or valacyclovir may cause headaches, dizziness, skin rashes, and gastrointestinal problems (nausea, vomiting, diarrhea). 

Amifostine Amifostine is incompatible with many drugs such as acyclovir sodium, amphotericin, cefoperazone sodium, hydroxyzine hydrochloride, miconazole, minocycline hydrochloride, and prochlorpherazine edisylate.239 Care should be exercised when handling amyl nitrate, since it is highly flammable. Volatile nitrites, such as poppers, are abused and fatal adverse effects are reported.240,241... 

Like acyclovir, valacyclovir is a well-tolerated drug. The most common adverse effects of valacyclovir are headache and nausea. Other adverse events associated with valacyclovir administration include vonuting, weakness, cUzziness, and abdoiifinal pain. Thrombotic thrombocytopenic purpura/ hemolytic ureiiuc syndrome has also been reported in a few patients after high doses of valacyclovir, as has confusion, hallucinations, and nephrotoxicity (Curran and Noble, 2001 Perry and Faulds, 1996). 

Bean B, and Aeppli D. 1985. Adverse effects of high-dose intravenous acyclovir in ambulatory patients with acute herpes zoster. 

The antiherpes drugs include acyclovir, ganciclovir, and foscarnet. Famciclovir and valacydovir are j newer drugs very similar to acyclovir. All inhibit viral DNA polymerase. Acyclovir and ganciclovir do so j by first being phosphorylated by viral enzymes. As well as acting as a polymerase inhibitor, acyclovir j j triphosphate is incorporated into the viral DNA where it acts as a chain terminator. The mechanisms of j j action, activities, clinical uses, and adverse effects are discussed, j... 

Vidarabine is a purine nucleoside analogue active against herpes viruses, influenza viruses, and some RNA viruses. Use of vidarabine for treatment of herpes simplex and varicella-zoster infections has largely been supplanted by acyclovir because of the superior efficacy, fewer adverse effects, and easier administration of the latter agent. Vidarabine has been associated with significant gastrointestinal, neurologic, and hematopoietic toxicities. Patients with renal insuffi-... 

Clinical uses and toxicity The drug is used for prophylaxis and treatment of cytomegalovirus (CMV) infections (including CMV retinitis) and has activity against ganciclovir-resistant strains of this virus (Table 49-1). Foscarnet inhibits herpes DNA polymerase in acyclovir-resistant strains that are thymidine kinase-deficient and may suppress such resistant herpetic infections in patients with AIDS. Adverse effects include nephrotoxicity (30% incidence) with disturbances in electrolyte balance (especially hypocalcemia), genitourinary ulceration, and CNS effects (headache, hallucinations, seizures). 

Johnson R, Douglas J, Corey L, Krasney H Adverse effects with acyclovir and meperidine Atm Intern Med(mS) 103.962-3... 

Within 2 weeks of using 1% trifluridine solution, 97% of cases resolve. Although drug-resistant HSV is rare, it is possible and should be considered if there is no improvement within the first few days. If there is no improvement or an adverse reaction occurs, use of a different antiviral is indicated. Acyclovir 3% ointment, although not commercially available for ophthalmic use in the United States, has been shown to be effective and well tolerated... 

Adverse reactions arc few. Some patients experience w-ca.sional gastrointestinal up.set. di/z.ines.s. headache, lethargy. and joint pain. An ointment composed of S% acyclovir in a polyethylene glycol base is available for the treatment of initial, mild episodes of herpes genitalis. The ointment is not an effective preventer of recurrent episodes. 

Acyclovir-resistant HSV has been isolated from patients with AIDS. The primary mechanism of resistance appears to be a deficiency in viral thymidine kinase. Strategies that have been employed for management of severe acyclovir-resistant HSV infections include increasing the dose of acyclovir, discontinuing acyclovir, and use of an alternative antiviral agent. Vidarabine and foscarnet, because they do not require phosphorylation by thymidine kinase, are examples of potential alternative agents. A randomized comparison of foscarnet and vidarabine indicated that foscarnet is more effective and associated with fewer adverse reactions than vidarabine. ... 

Trifluridine is FDA approved for treatment of primary keratoconjunctivitis and recurrent epithelial keratitis owing to HSV types 1 and 2. Topical trifluridine is more active than idoxuridine and comparable with vidarabine in HSV ocular infections. Adverse reactions include discomfort on instillation and palpebral edema. Hypersensitivity reactions, irritation, and keratopathy are uncommon. Topical trifluridine also is effective in some patients with acyclovir-resistant HSV cutaneous infections. 

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