Pentamidine Didanosine

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... 

Didanosine, 1-asparaginase, lamivudine, metformin, pentamidine, statins, stavudine, sulindac, valproic acid, and zalcitabine... 

Drugs that may interact with zalcitabine include antacids, chloramphenicol, cisplatin, dapsone, didanosine, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine, cimetidine, metoclopramide, amphotericin, aminoglycosides, foscarnet, antiretroviral nucleoside analogs, pentamidine, and probenecid. 

PENTAMIDINE ISETIONATE NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS t adverse effects with didanosine, tenofbvir and zidovudine Additive toxicity Monitor FBC and renal function closely. Consider stopping didanosine while pentamidine is required for Pneumocystis jiroveci pneumonia... 

Lamivudine inhibits the intracellular phosphorylation of zalcitabine and antagonizes zalcitabine s antiretroviral activity in vitro, although the clinical significance of this interaction is unknown. Probenecid increases the zalcitabine AUC by about 50%, probably through inhibition of tubular secretion cimetidine increases the AUC by 36% via an unknown mechanism. Zalcitabine should be avoided in patients with a history of pancreatitis or neuropathy because the risk and severity of both complications increase. Coadministration of other drugs that cause pancreatitis or neuropathy also will increase the risk and severity of these symptoms. Ethambutol, isoniazid, vincristine, cisplatin, and pentamidine, as well as the antiretroviral drugs didanosine and stavudine, therefore, should be avoided. 

Additive pancreatic toxicity has been described with zalcitabine and intravenous pentamidine, and is expected when didanosine or stavudine are given with other drugs that can cause pancreatitis. An isolated case describes pancreatitis with lamivudine and aza-thioprine. 

The manufacturers of didanosine have a similar recommendation and state that, if concurrent use is unavoidable, there should be close observation. Similarly, other authors recommend temporarily discontinuing didanosine in patients needing systemic pentamidine or sulfonamide-containing regimens. The UK manufacturer of stavudine recommends that patients receiving concurrent treatment with drugs known to cause pancreatitis should be carefully observed, and the US manufacturer specifically recommends caution with combined use of didanosine and stavudine, see NRTIs + NRTIs , p.800. Note that hydroxycarbamide (hydroxyurea) may increase the risk of pancreatitis with didanosine and stavudine, and the combination should probably be avoided, see NRTIs + Hydroxycarbamide , p.799. 

Cytotoxicity Acetaminophen, didanosine, isoniazid, L-asparaginase, mesalamine, metronidazole, nucleoside reverse transcriptase inhibitors (NRTIs), pentamidine, protease inhibitors, sitagliptin, statins, valproic acid... 

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