nelfinavir mesylate

nelfinavir mesylate

Viracept

Pharmacologic class: Protease inhibitor

Therapeutic class: Antiretroviral

Pregnancy risk category B

Action

Inhibits action of human immunodeficiency virus (HIV) protease and prevents cleavage of viral polyproteins, resulting in production of immature, noninfectious virus

Availability

Oral powder: 50 mg/1 g powder (1 g powder/level scoopful)

Tablets: 250 mg, 625 mg

⊘Indications and dosages

➣ HIV infection

Adults and children older than age 13: 750 mg P.O. t.i.d. or 1,250 mg b.i.d., given with other antiretrovirals

Children ages 2 to 13: 20 to 30 mg/kg P.O. t.i.d., given with a meal or light snack

Contraindications

• Hypersensitivity to drug or its components
• Concurrent use of astemizole, cisapride (not available in U.S.), amiodarone, dihydroergotamine, ergotamine, midazolam, quinidine, rifampin, terfenadine, or triazolam

Precautions

Use cautiously in:
• hemophilia, diabetes mellitus, hepatic impairment
• phenylketonuria (oral powder contains phenylalanine)
• breastfeeding patients.

Administration

• Give tablets with food.
• For adult who can't swallow tablets whole, crush and mix in food or dissolve in small amount of water. Have patient consume mixture immediately, or refrigerate for up to 6 hours.
• For child who can't swallow tablets, mix oral powder with small amount of water, formula, or milk. Have child consume mixture immediately, or refrigerate for up to 6 hours.
• Don't mix powder with water in its original container.
• Don't mix powder with acidic juice (combination produces bitter taste).
☞ Don't give concurrently with amiodarone, astemizole, cisapride, dihydroergotamine, ergotamine, midazolam, quinidine, rifampin, terfenadine, or triazolam.

Route	Onset	Peak	Duration
P.O.	Rapid	2-4 hr	8 hr

Adverse reactions

CNS: anxiety, depression, dizziness, drowsiness, emotional lability, headache, hyperkinesia, insomnia, malaise, migraine headache, sleep disorders, weakness, myasthenia, paresthesia, suicidal ideation, seizures

EENT: acute iritis, rhinitis, sinusitis, pharyngitis

GI: nausea, diarrhea, abdominal pain, flatulence

GU: nephrolithiasis, sexual dysfunction

Hematologic: anemia, leukopenia, thrombocytopenia

Metabolic: dehydration, hyperuricemia, hypoglycemia

Musculoskeletal: joint pain, arthritis, back pain, myalgia, myopathy

Respiratory: dyspnea, bronchospasm

Skin: pruritus, rash, sweating, fungal dermatitis, folliculitis, urticaria

Other: fever, body fat redistribution, allergic reactions

Interactions

Drug-drug. Amiodarone, dihydroergotamine, ergotamine, midazolam, quinidine, triazolam: excessive sedation, vasoconstriction, serious arrhythmias

Carbamazepine, phenobarbital, phenytoin, rifampin: decreased nelfinavir blood level and efficacy

Hormonal contraceptives: decreased contraceptive blood level and efficacy

Rifabutin: decreased rifabutin metabolism and effects

Drug-diagnostic tests. Lipids: increased levels

Drug-food. Most foods: enhanced drug absorption

Drug-herbs. St. John's wort: decreased nelfinavir blood level and efficacy

Patient monitoring

☞ Watch for signs and symptoms of depression and suicidal ideation.
• Evaluate neurologic status closely, particularly for seizures and sensorimotor dysfunction.
• Assess CBC, lipid panel, uric acid level, and HIV-specific tests.
• Watch for secondary infections, particularly fungal and EENT infections.

Patient teaching

• Advise patient to take with a meal or snack. Inform him that he may mix oral powder with nonacidic fluids.
• Tell patient he may take missed dose up to 1 hour before next scheduled dose.
☞ Instruct patient to report depression or suicidal thoughts.
• Tell patient that drug may predispose him to other infections, especially fungal and EENT infections. Advise him to avoid crowds and to wash hands often and thoroughly.
• Tell patient with phenylketonuria (or caregiver) that powder contains phenylalanine.
• Instruct female patient to use reliable barrier contraception.
• Advise female patient not to breastfeed, because breast milk may transfer HIV to infant.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, strength, and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.