Rifampin
Contraindicated
Textbook
Significantly reduced darunavir concentrations, leading to loss of antiviral effectiveness.
Contraindicated.
Source: G&G 14e · p1245-1266
Drug reference
Darunavir
HIV protease inhibitor (with pharmacokinetic booster) · Antiretroviral
START
Naïve: 800 mg + ritonavir 100 mg once daily with food
TYPICAL MAX
1200 mg/day darunavir (PI-experienced BID regimen)
STOP IF
Severe skin reaction (SJS/DRESS), significant hepatotoxicity, or pancreatitis
WATCH
LFTs, lipids, glucose; comprehensive interaction review (booster CYP3A4)
CDSCO approvedSchedule HATC J05AE10
KDIGO 2024 + manufacturer label
- ONSET
- 1h · absorption
- PEAK
- 3h · Tmax boosted
- t½
- 15h · t½ boosted
- DURATION
- 1d · once-daily
EXCRETION
Mainly faecal (~80%); ~14% renal
route + CYP
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
Avoid once-daily darunavir/cobicistat in pregnancy (sub-therapeutic levels); twice-daily darunavir/ritonavir acceptable.
FDA category + note
Top interactionssee all 12 →
- RifampinContraindicatedTextbookG&G 14e · p1245-1266
- SimvastatinContraindicatedDatabaseKimi deep-research + Cla · p948
- Strong Cyp3a4 InducersContraindicatedDatabaseKimi deep-research + Cla
- AtorvastatinSevereTextbook-citedKDT 7e · p948
Mechanism
Non-peptidic HIV-1 protease inhibitor that blocks viral polyprotein cleavage and inhibits HIV-1 replication; high genetic barrier to resistance; co-administered with ritonavir or cobicistat as PK booster.
Indications
HIV-1 infection (treatment-naïve or experienced, with PK booster + other antiretrovirals)
Dosing
- Adult
- Treatment-naïve / no PI mutations: 800 mg + ritonavir 100 mg once daily (with food). Treatment-experienced (any PI mutation): 600 mg + ritonavir 100 mg twice daily.
- Pediatric
- ≥3 y: weight-banded (specialist).
- Renal adjustment
- No adjustment (oral).
- Hepatic adjustment
- Mild–moderate: no adjustment; severe: not recommended.
- Geriatric
- No specific adjustment.
- Max dose
- 1200 mg/day darunavir (with 200 mg ritonavir if twice-daily)
Pharmacokinetics
Onset
Viral suppression over weeks
Peak effect
~2.5–4 h (Tmax, boosted)
Duration
~24 h (once-daily) or ~12 h (twice-daily)
Half-life
~15 h (boosted)
Bioavailability
~37%; food increases ~30%
Protein binding
~95%
Metabolism
CYP3A4 (inhibited by ritonavir / cobicistat)
Excretion
Mainly faecal (~80%); ~14% renal
Contraindications
- Co-administration with potent CYP3A4-dependent drugs with serious toxicity (alfuzosin, ergot, lovastatin/simvastatin, pimozide, etc.)
- Severe hypersensitivity / sulfonamide allergy (cross-reactivity caution)
- Severe hepatic impairment
Side effects
Common
DiarrhoeaNauseaHeadacheRashHyperlipidaemiaTransaminase elevation
Serious
- Severe rash / SJS / DRESS (sulfonamide moiety)
- Hepatotoxicity (esp. with HBV/HCV)
- Diabetes / new-onset hyperglycaemia (PI class)
- Immune reconstitution inflammatory syndrome
Pregnancy & lactation
Pregnancy
Avoid once-daily darunavir/cobicistat in pregnancy (sub-therapeutic levels); twice-daily darunavir/ritonavir acceptable.
Lactation
Per regional HIV/breastfeeding guidance.
Drug interactions
Simvastatin
Contraindicated
Database
Ritonavir CYP3A4 inhibition
Contraindicated
Source: Kimi deep-research + Cla · p948
Strong Cyp3a4 Inducers
Contraindicated
Database
Markedly reduced darunavir exposure
Contraindicated
Source: Kimi deep-research + Cla
Atorvastatin
Severe
Textbook-cited
Increased risk of rhabdomyolysis and myopathy.
Avoid concurrent use; if needed, use lowest statin dose
Source: KDT 7e · p948
Carbamazepine
Severe
Textbook-cited
Carbamazepine toxicity (diplopia, ataxia, drowsiness)
Avoid concurrent use or adjust dose with monitoring
Source: KDT 7e · p948
Cyclosporine
Severe
Textbook-cited
Nephrotoxicity and immunosuppression toxicity
Monitor cyclosporine levels and reduce dose
Source: KDT 7e · p948
Glibenclamide
Severe
Textbook-cited
Hypoglycemia
Avoid concurrent use or adjust dose
Source: KDT 7e · p948
Gliclazide
Severe
Textbook-cited
Hypoglycemia
Avoid concurrent use or adjust dose
Source: KDT 7e · p948
Glimepiride
Severe
Textbook-cited
Hypoglycemia
Avoid concurrent use or adjust dose
Source: KDT 7e · p948
Glipizide
Severe
Textbook-cited
Hypoglycemia
Avoid concurrent use or adjust dose
Source: KDT 7e · p948
Lovastatin
Severe
Textbook-cited
Increased risk of rhabdomyolysis and myopathy
Avoid concurrent use; if needed, use lowest statin dose
Source: KDT 7e · p948
Phenytoin
Severe
Textbook-cited
Phenytoin toxicity
Avoid concurrent use or adjust phenytoin dose with monitoring
Source: KDT 7e · p948
Related guidelines
Ask House about Darunavir
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20