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Saquinavir

Antiretroviral

Also known as Saquinavir mesilate, SQV

Antiretroviral
CDSCO approvedSchedule H
EXCRETION
not curated
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
not curated
Top interactionssee all 12
  • CilostazoleContraindicatedTextbookKDT 7e · p555
  • DomperidoneContraindicatedDatabase
  • AbarelixSevereDatabaseDDInter
  • AbemaciclibSevereDatabaseDDInter

Mechanism

Saquinavir is a peptidomimetic HIV protease inhibitor that was designed to mimic the phenylalanine-proline cleavage site of the HIV Gag-Pol polyprotein, fitting into the active site of the HIV aspartyl protease and competitively blocking substrate access. This prevents the proteolytic processing of viral polyproteins into mature structural and enzymatic components, resulting in production of non-infectious, immature virions. Its oral bioavailability is poor (~4% alone) and it is used with ritonavir boosting.

Indications

HIV infection in combination with other antiretrovirals in patients previously treated with antiretroviral therapy (with low-dose ritonavir)HIV infection in combination with other antiretrovirals in patients not previously treated with antiretroviral therapy (with low-dose ritonavir)HIV (in combination regimens)

Dosing

Adult
For previously treated patients: 1 g every 12 hours (with low-dose ritonavir). For not previously treated patients: 500 mg every 12 hours for 7 days, then increased to 1 g every 12 hours (with low-dose ritonavir).
Renal adjustment
Use with caution if eGFR less than 30 mL/minute/1.73 m2.
Hepatic adjustment
Manufacturer advises caution in moderate impairment (limited information available); avoid in decompensated liver disease.

Pharmacokinetics

Half-life
2–8 hours (plasma)
Bioavailability
15% (oral)
Metabolism
Induces its own metabolism
Excretion
Extensively metabolized mainly by CYP3A4

Contraindications

  • Bradycardia
  • Congenital QT prolongation
  • Electrolyte disturbances
  • Heart failure with reduced left ventricular ejection fraction
  • History of symptomatic arrhythmias

Side effects

Common
BurpingConstipationDry lipsLibido decreasedLipoatrophyParaesthesiaphotosensitivity (can occur)frequent side effects
Serious
  • Mucosal ulceration
  • Renal impairment
  • Visual impairment
  • QT interval prolongation
  • Arrhythmias
  • Palpitation
  • Syncope

Drug interactions

Cilostazole
Contraindicated
Textbook

Increased plasma levels and toxicity of cilostazole.

Should not be administered along with inhibitors of CYP3A4.

Source: KDT 7e · p555

Domperidone
Contraindicated
Database

Significantly increased domperidone plasma levels, leading to increased risk of QT prolongation and Torsades de Pointes (TdP)

Concomitant use is contraindicated. Avoid co-administration.

Abarelix
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Abemaciclib
Severe
Database

Drug interaction classified as: metabolism

Source: DDInter

Abiraterone
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Acalabrutinib
Severe
Database

Drug interaction classified as: metabolism

Source: DDInter

Acebutolol
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Adenosine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Alfentanil
Severe
Database

Drug interaction classified as: metabolism

Source: DDInter

Alfuzosin
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Alimemazine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Amiodarone
Severe
Database

Increase amiodarone levels.

Source: DDInter

Related guidelines

Other Antiretroviral drugs

Ask House about Saquinavir

Continue into a citation-backed clinical answer with the drug context already attached.

Sources: KD Tripathi 7e, Katzung·Verified: 2026-05-10 · House clinical team