Meds and you

30 September 2013


Saquinavir is an antiretroviral. Antiretrovirals are drugs that suppress the activity or replication of retroviruses such as HIV.


Saquinavir is the active ingredient of Invi-Rase Capsules (Nappi Code: 825697-019).

General information
Saquinavir is an antiretroviral. Antiretrovirals are drugs that suppress the activity or replication of retroviruses such as HIV.

This specific antiviral is classified as a protease inhibitor, meaning that it blocks an enzyme which plays an essential role in viral multiplication. It interferes with the ability of the virus to make copies of itself.

In South Africa saquinavir is registered for the treatment of infection with the human immunodeficiency virus (HIV), often in combination with other antiretroviral drugs.

If not treated, HIV will advance to weaken the body's immune system, gradually chipping away to create grounds for other infections which the body will find more and more difficult to protect itself against. HIV develops into acquired immune deficiency syndrome (AIDS) when your immune system has been severely weakened.

For saquinavir to be effective it has to be taken regularly. By skipping even a few doses the risk for treatment failure increases substantially. Try to ensure that you take all your doses, and at the correct time.

It should be understood that saquinavir is not a cure for HIV or AIDS, but one of a variety of drugs that only restricts the advance of the virus, keeping the immune system up-and-running. It is used in combination with other antiretroviral drugs and should not be prescribed on its own.

Saquinavir does not reduce transmission of HIV; you can still infect another person with the virus and the use of appropriate precautions to prevent it spreading to other persons is highly recommended.

How does saquinavir work?
After a human T cell is infected with HIV, the virus needs to multiply to spread to other cells. A crucial part of HIV multiplication is the production of an enzyme called protease which is essential for the assembly of new viral copies. This drug interferes with the working of this enzyme, thereby leaving the new copies of the virus immature and non-infectious.

Fast facts Drug schedule: schedule 4
Available as:saquinavir is available as capsules.
What does it do? Saquinavir is an anti-viral drug.
Overdose risk: medium
Dependence risk: low
Is saquinavir available as a generic? no
Is saquinavir available on prescription only? yes

User information Dietary advice: saquinavir should be taken with or after a meal. At least 1.5 litres of water should be consumed daily while being treated with this drug to reduce the risk of kidney stones.
Stopping this medicine: do not stop taking this drug without consulting your doctor.
Prolonged use: side-effects may develop with long-term use; frequent blood tests may be required with prolonged therapy to prevent serious blood disorders and to determine liver function.

Special precautions
Consult your doctor before using this drug if:

  • you have known liver or kidney problems

  • you have been diagnosed with a condition that increases your risk of bleedin

  • you have diabetes

  • you are taking other medication

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.
Breastfeeding: avoid. Not only can HIV infection be passed to your baby through breast milk, but saquinavir is also present and transmitted in breast milk.
Porphyria: avoid. This medication may cause serious adverse effects. Consult your doctor before use.
The elderly: caution is advised in the elderly as side effects may be more severe.
Infants and children: this medication is not intended for use in children under the age of 16.
Driving and hazardous work: caution is advised as use of this medication may lead to dizziness or light-headedness. Avoid such activities until you know how this medication affects you.
Alcohol: avoid concomitant use of alcohol with this medication.

Possible side effects

Side Effect
Consult your doctor

Only if severe
In all cases






abdominal pain




taste disturbance




mouth ulcers






abnormal body fat distribution


skin rash


muscle weakness


muscle pain




carbamazepine, phenytoin, phenobarbitone reduced effect of saquinavir
ketoconazole increased risk of saquinavir toxicity
dexamethasone reduced effect of saquinavir
didanosine take the 2 drugs at least 2 hours apart
grapefruit juice increased risk of saquinavir toxicity
ranitidine increased risk of saquinavir toxicity
rifampicin/ St John's wort reduced effect of saquinavir
astemizole/cisapride/ pimozide/ terfenadine increased risk of cardiac toxicity
simvastatin and other similar cholesterol lowering drugs increased risk of muscle wasting

Many other drugs may interact with saquinavir. It is important to consult your doctor or pharmacist before combining any drug with saquinavir.

Disease interactions
Contact your doctor in case of liver/kidney disease, diabetes, or you have been diagnosed with a condition that increases your risk of bleeding.

Overdose action
A small overdose is no cause for concern. In case of intentional large overdose seek emergency medical attention.

Recommended dosage
Adults, oral: 600 mg 8 hourly

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.

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