BULLDOG MEDICAL

DETAILED EXPLANATION

 

Action: virus-specific thymidine kinase convert acyclovir to acyclovir monophosphate, which is

             then converted to acyclovir triphosphate by other cellular enzymes.

 

Availability: prescription only.

 

Class (Chemical): purine nucleoside analog.

 

Class (Functional): antiviral.

 

Contraindications: hypersensitivity to acyclovir, valacyclovir, or milk protein.

 

Dose: Herpes Simplex: Adult PO: 400mg 3x/day for 5 days OR 200mg 5x/day for 5 days

                                        Over 12 IV: 5mg/kg over 1hr q8hrs for 7 days

                                        3mos to 12yrs IV: 10mg/kg q8hrs for 7 days

                                        Neonate IV: 10mg/kg q8hrs for 10 days

           Herpes Simplex Encephalitis: Adult IV: 10mg/kg over 1hr q8hrs for 10 days

                                                               3mos to 12yrs IV: 10-15mg/kg q8hrs for 4-21 days

                                                               Birth to 3mos IV: 20mg/kg q8hrs for 21 days

                                                               Premature to Neonate IV: 10mg/kg q12hrs for 14-21

                                                                                                            days

           Herpes Labialis, Recurrent: Over 12yrs TOP: apply 5x/day for 4 days

                                                                                          begin as soon as symptoms appear

           Herpes Zoster: Adult PO: 800mg q4hrs for 7-10 days

                                     Adult IV: 10mg/kg q8hrs for 7 days

           Varicella: Over 2yrs PO: 10mg/kg (max 800mg) 4x/day for 5 days

           Genital Herpes, Initial: Adult PO: 400MG 3x/day OR 200mg 5x/day for 7-10 days

                                                   Adult TOP: apply for 5 days

                                                   Adult IV: 5mg/kg q8hrs OR 750mg/m2/day divided q8hrs for 7-

                                                                    10 days

           Genital Herpes, Episodic: Adult PO: 400mg 3x/day OR 800mg 2x/day for 5 days

                                                                          OR 800mg 3x/day for 2 days

                                                                          Initiate within 1 day of lesion onset

           Genital Herpes, Suppression: Adult PO: 400mg 2x/day OR 200mg 3-5x/day for up to

                                                                                12 months

 

Interactions: zidovudine will increase CNS side effects; increase levels of probenecid and put                               patient at risk for toxicity; aminoglycosides will increase risk of nephrotoxicity;

                       increase the concentrations of entecavir, pemetrexed, tenofovir, and theophylline;

                       decrease action of hydantoins, valproic acid.

 

Labs: elevated ALT/AST; increased BUN and creatinine; decrease in WBCs.

 

Notes: does not cure infections, just controls symptoms.

 

Off-Label Use: Bell’s palsy when used in conjunction with prednisolone; prevention of

                          cytomegalovirus, Epstein-Barr virus, esophagitis, hairy leukoplakia, herpes

                          labialis, herpes simplex, herpes simplex ocular, keratoconjunctivitis, pharyngitis,

                          pneumonitis, postherpetic neuralgia, proctitis, stomatitis, tracheobronchitis,

                          varicella.

 

Precautions: breastfeeding; dehydration; electrolyte imbalance; hypersensitivity to famciclovir,

                      ganciclovir, or penciclovir; obesity; pregnancy; renal, hepatic, or neurologic disease.

 

Report to Provider: difficulty breathing; lower back pain.

 

Routes: BUC; IV; PO; TOP.

 

Side Effects: confusion; hallucinations; tremors; lethargy; seizures; dizziness; headache;

                      encephalopathic changes; gingival hyperplasia; nausea; vomiting; diarrhea;

                      abdominal pain; colitis; changes in menses; hematuria; acute renal failure;

                      hemolytic uremic syndrome; thrombotic thrombocytopenia purpura; leukopenia (in

                      immunocompromised patients); urticaria; rash; pruritis; pain or phlebitis at IV site;

                      alopecia; unusual sweating; Stevens-Johnson syndrome; joint pain; angioedema;

                      anaphylaxis.

 

Uses: herpes simplex virus (mucocutaneous); herpes genitalis (HSV-1, HSV-2); varicella; herpes

          zoster; herpes simplex encephalitis.

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Reference: Mosby's Nursing Drug Reference