nelfinavir

Absorption: Well absorbed after oral administration.

Distribution: Widely distributed to tissues.

Protein Binding: >98%.

Metabolism/Excretion: Primarily metabolized in the liver via the CYP2C19 and CYP3A4 isoenzymes; the CYP2C19 isoenzyme exhibits genetic polymorphism; 15–20% of Asian patients and 3–5% of Caucasian and Black patients may be poor metabolizers and may have significantly ↑ nelfinavir concentrations and an ↑ risk of adverse effects. Excreted in feces as metabolites (78%) or unchanged drug (22%); minimal renal excretion.

Half-Life: 3.5–5 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	rapid	2–4 hr	8 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Concurrent use of amiodarone, ergot derivatives, quinidine, lurasidone, pimozide, alfuzosin, sildenafil (Revatio), simvastatin, lovastatin, triazolam, or rifampin;
OB: Pregnancy;
Lactation: Breastfeeding should be avoided in women with HIV.

Use Cautiously in:

Hemophilia (↑ risk of bleeding);
Diabetes (may exacerbate condition);
Hepatic impairment.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: pruritus, rash, sweating, urticaria

EENT: acute iritis, pharyngitis, rhinitis, sinusitis

Endo: fat redistribution, hyperglycemia

F and E: dehydration

GI: diarrhea, anorexia, dyspepsia, epigastric pain, flatulence, GI bleeding, hepatitis, ↑liver enzymes, nausea, oral ulcerations, pancreatitis, vomiting

GU: nephrolithiasis, sexual dysfunction

Hemat: anemia, leukopenia, thrombocytopenia

Metab: hyperlipidemia, hyperuricemia

MS: arthralgia, arthritis, back pain, myalgia, myopathy

Neuro: anxiety, depression, dizziness, drowsiness, emotional lability, headache, hyperkinesia, insomnia, malaise, migraines, myasthenia, paresthesia, SEIZURES, sleep disorders, SUICIDAL IDEATION, weakness

Resp: dyspnea

Misc: allergic reactions, fever, immune reconstitution syndrome

Interactions ⬆ ⬇

Drug-drug:

↑levels and risk of toxicity from amiodarone, ergot derivatives (dihydroergotamine, ergotamine, methylergonovine), lovastatin, lurasidone, pimozide, quinidine, sildenafil (Revatio), simvastatin, alfuzosin, or triazolam; concurrent use contraindicated.
.
Rifampin may ↓ levels and promote resistance to its effects; concurrent use contraindicated.
↑risk of myopathy with atorvastatin; do not exceed atorvastatin dose of 40 mg/day.
May ↑ effects of rifabutin (dose of rifabutin should be ↓ by 50%), carbamazepine, phenobarbital, or phenytoin ; avoid concurrent use with rifampin.
Ketoconazole, or ritonavir may ↑ levels and risk of toxicity.
May ↓ levels of methadone; dose of methadone may need to be ↑.
↑levels of cyclosporinetacrolimus, sirolimus, and azithromycin.
Nevirapine and omeprazole may ↓ levels and effectiveness.
May ↓ levels and effectiveness of hormonal contraceptives.
May ↑ levels and risk of toxicity of phosphodiesterase type 5 inhibitors (PDE5) causing hypotension, visual changes, priapism; ↓ starting doses not to exceed 25 mg within 48 hr for sildenafil, 2.5 mg every 24 hr for vardenafil and 10 mg every 72 hr for tadalafil.
May ↑ risk of toxicity ofsalmeterol; concurrent use not recommended.
May ↑ bosentan levels; initiate bosentan at 62.5 mg once daily or every other day.
May ↑ tadalafil (Adcirca) levels; initiate tadalafil (Adcirca) at 20 mg once daily.
May ↑ levels and risk of toxicity of colchicine; ↓ dose of colchicine; do not administer colchicine if patients have renal or hepatic impairment.
May ↑ levels and risk of bleeding of warfarin ; routinely monitor INR.
May ↑ levels and risk of toxicity of quetiapine ; ↓ quetiapine dose to 1/6 of current dose

Drug-Natural Products:

St. John's wort may ↓ levels and effectiveness.

Drug-Food:

Food↑ absorption.

Route/Dosage ⬆ ⬇

PO (Adults and Children ≥13 yr): 750 mg 3 times daily or 1250 mg twice daily.
PO (Children 2–13 yr): 44–55 mg/kg twice daily or 25–35 mg/kg 3 times daily (not to exceed 2500 mg/day).

Availability ⬆ ⬇

Tablets: 250 mg; 625 mg

Assessment ⬆ ⬇

Assess patient for change in severity of HIV symptoms and opportunistic infections during therapy.

Lab Test Considerations:

Monitor viral load and CD4 cell counts regularly during therapy.
May cause hyperglycemia.
May cause ↑ serum AST, ALT, total bilirubin, alkaline phosphatase, LDH, and CK concentrations.
May cause anemia, leukopenia, thrombocytopenia, hyperlipidemia, and hyperuricemia.
May affect warfarin concentrations. Monitor INR frequently, especially when beginning warfarin therapy.

Implementation ⬆ ⬇

Do not confuse Viracept with Viramune.
PO: Administer with a meal. Tablets are film-coated to make swallowing easier.
- Patients who are unable to swallow tablet may place tablet in small amount of water. Once dissolved, mix the cloudy liquid well and drink immediately. Rinse glass with water and swallow to make sure entire dose is consumed.

Patient/Family Teaching ⬆ ⬇

Emphasize the importance of taking nelfinavir exactly as directed at evenly spaced times throughout the day. Do not take more than prescribed amount and do not stop taking without consulting health care professional. Take missed doses as soon as remembered; do not double doses.
Instruct patient that nelfinavir should not be shared with others.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially St. John's wort. Advise patient to find out which medications cannot be taken with nelfinavir.
Inform patient that nelfinavir does not cure HIV or prevent associated or opportunistic infections. Nelfinavir may reduce the risk of transmission of HIV to others through sexual contact or blood contamination. Caution patient to avoid sexual contact or to use a condom and to avoid sharing needles or donating blood to prevent spreading HIV to others. Advise patient that the long-term effects of nelfinavir are unknown at this time.
Inform patient that nelfinavir may cause hyperglycemia. Advise patient to notify health care professional if increased thirst or hunger; unexplained weight loss; increased urination; fatigue; or dry, itchy skin occurs.
Advise patient that if diarrhea occurs, it can usually be controlled with OTC antidiarrheals, such as loperamide, which slow GI motility.
Inform patient that redistribution and accumulation of body fat may occur, causing central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, breast enlargement, and cushingoid appearance. The cause and long-term effects are not known.
Immune reconstitution syndrome may trigger opportunistic infections or autoimmune disorders. Notify health care professional if symptoms occur.
Rep: May cause fetal harm. May cause liver failure in pregnant patients; consider alternative antiretroviral drugs. Advise females of reproductive potential taking oral contraceptives to use a nonhormonal method of birth control during nelfinavir therapy. If pregnancy is suspected, notify health care professional promptly. Inform pregnant women of the Antiretroviral Pregnancy Registry that monitors pregnancy outcomes in women exposed to nelfinavir during pregnancy. Enroll patient by calling 1-800-258-4263. Advise female patient to avoid breastfeeding during therapy.
Emphasize the importance of regular follow-up and blood counts to determine progress and monitor for side effects.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇