Acyclovir interactions

All acyclic and carbocyclic guanosine analogues depicted in Fig. 1 follow the same modus operandi as exemplified for acyclovir (ACV) in Fig. 5, in that they need three phosphorylations to be converted to their active metabolite, the triphosphate form, which then interacts with the target enzyme, the viral DNA polymerase, as a chain terminator (De Clercq 2002). In its DNA chain-terminating... 

Drugs that may interact with acyclovir include hydantoins, probenecid, theophylline, valproic acid, and zidovudine. 

Foscarnet (Foscavir) [Antiviral] Uses CMV retinitis acyclovir-resistant hCTpes Infxns Action -1- Viral DNA polym ase RT Dose CMV retinitis Induction 60 mg/kg IV qSh or 100 mg/kg ql2h X 14—21 d Meant 90-120 mg/kg/dIV (Moo.-Fiti ) Acyclovir-resistant HSV Induction 40 mg/kg IV q8-12h x 14—21 d use central line -1- w/ renal impair Caution [C, —] T Sz potential w/ fluoroquinolones avoid n hrotoxic Rx (cyclosporine, aminoglycosides, ampho B, protease inhibitors) Contra CrCl <0.4 mL/min/kg Disp Inj SE Nephrotox, electrolyte abnormalities Interactions T Risks of Sz W/ quinolones t risks of n hrotox W/ aminoglycosides, amphotCTicin B, didanosine, pentamidine, vancomycin EMS Known to cause electrolyte disturbances (extremity numbness paresthesia indicates electrol5rte unbalance) monitor ECG OD May cause extremity numbing, and Szs hydrate w/ IV fluids... 

Astragalus Astragalus membranaceus) Uses Rx of resp infxns, enhancement of immune system, HF Action Root saponins t diuresis, -1- BP anti-inflammatory action related to the stimulation of macrophages, t antibody formation t T-lymphocyte proliferation Available forms Caps/tabs 1-4 g tid, PO Liq ext 4-8 mL/d (1 2 ratio) dry ext 250 mg (1 8 ratio) tid, PO Notes E Immunosuppression w/ doses >28 g Interactions t Effect OF acyclovir, anticoagulants, antihypertensives, antithrombotics, antipits, intCTleukin 2, intCTferon X effect OF cyclophosphamide EMS t Risk of bleeding... 

The potential for drug interactions, particularly with other drugs that are actively secreted by the proximal tubules, should be considered. Probenecid has been shown to inhibit the renal clearance of acyclovir. Cyclosporine and other nephrotoxic agents may increase the risk of renal toxicity of acyclovir. 

Drug interactions In a randomized, double-blind study, Zenapax or placebo was added to an immunosuppressive regimen of cyclosporine, mycophenolate mofetil, and steroids to assess tolerability, pharmacokinetics, and drug interactions. The addition of Zenapax did not result in an increased incidence of adverse events or a change in the types of adverse events reported. The following medications have been administered in clinical trials with Zenapax with no incremental increase in adverse reactions cyclosporine, mycophenolate mofetil, ganciclovir, acyclovir, azathioprine, and corticosteroids. 

The final step added a group that would interact with the phosphate binding site either directly or via electrostatic interactions. We could not use phosphate itself, because phosphate-containing compounds are not metabolically stable and have difficulty passing through cell membranes intact. Acyclovir diphosphate, which is not membrane permeable and is subject to extracellular metabolism, is a good example. 

Drug Interactions Acyclovir Antacids with magnesium and aluminum hydroxides Cholestyramine Drugs that alter gastrointestinal flora may interact with mycophenolate mofetil by disrupting enterohepatic recirculation Probenecid... 

NaCIO is an acknowledged novel absorption enhancer for ampicillin sodium [99], glycyr-rhizin [100,101], gentamicin [102], phenoxymethyl penicillin [103], cefoxitin sodium [104,105], and acyclovir [106], Takahashi et al. [107] reported that the enhanced membrane permeability of phenolsulfonphthalein depends on the disappearance kinetics of CIO from the loop and its calcium ion sequestration capacity. The enhancing mechanisms of NaCIO are proposed to be involved in (1) Ca2+ sequestration, (2) increase in pore size and solvent drag, (3) interaction with membrane proteins and lipids, and (4) increase in the intracellular calcium level [104,105,108-111],... 

Sinko, P. J., and Balimane, P. V. Carrier-mediated intestinal absorption of valacyclovir, the L-valyl ester prodrug of acyclovir I. Interactions with peptides, organic anions and organic cations in rats. Biopharm. Drug Dispos. 19(4) 209-217, 1998. 

Probenecid has been reported to inhibit renal elimination of many drugs acyclovir (325,326), allopurinol (327), bumetanide (328), cephalosporins (329-334), cidofovir (335), ciprofloxacin (336), famotidine (337), fexofenadine (338), furosemide (339), and oseltamivir (Ro 64-0802) (340). Recent studies have elucidated that probenecid is a potent inhibitor of renal organic anion transporters (OAT1 and OAT3) with the Ki values lower than the unbound plasma concentration of probenecid, indicating the interaction with probenecid includes inhibition of the basolateral uptake process mediated by OAT1 and/or OAT3. 

De Bony F, Tod M, Bidault R, et al. Multiple interactions of cimetidine and probenecid with valaciclovir and its metabolite acyclovir. Antimicrob Agents Che-mother 2002 46 458 163. 

Sulfa ted amphiphilic a-, p-, and y-CDs were demonstrated to form 1 1 inclusion complexes with the antiviral drug acyclovir. Noncovalent interactions between... 

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