Saquinavir 500

Indications

Saquinavir is an antiretroviral medicine used to treat HIV-1 infection in adults. It is always used together with a low dose of Ritonavir (which raises Saquinavir levels in the blood) and with other HIV medicines as part of combination therapy. It does not cure HIV and does not stop the virus passing to others, but it helps keep the virus under control and protects the immune system.

How It Works

Saquinavir belongs to a group called protease inhibitors. HIV needs an enzyme called protease to cut long viral proteins into the working parts that make new, infectious virus. Saquinavir blocks this enzyme, so the new virus particles that are made are immature and cannot infect other cells. This lowers the amount of virus in the blood (viral load) and allows CD4 immune cells to recover.

Dosage and Administration

Take exactly as prescribed by your HIV doctor. In adults the usual dose is 1000 mg twice daily taken together with Ritonavir 100 mg twice daily, swallowed with or just after a meal. Your doctor may use a lower starting dose in the first week for people starting treatment for the first time. Take doses at the same times each day and never stop or skip doses, because missed doses allow the virus to become resistant.

Interactions

Saquinavir with Ritonavir interacts with a very large number of medicines. Always tell your doctor and pharmacist about every medicine, herbal product and supplement you use.

• Do not combine with medicines that prolong the QT interval of the heart, such as Amiodarone, Quinidine, Sotalol, some antipsychotics, Erythromycin, Clarithromycin or Moxifloxacin, unless a specialist advises it.
• Do not use with Rifampicin, St John's Wort, Simvastatin, Lovastatin, oral Midazolam, Triazolam, Ergotamine, Sildenafil for lung hypertension or Lurasidone.
• Levels of many drugs rise, including some statins, calcium channel blockers, Warfarin, Fentanyl, Colchicine and some antifungals.
• Hormonal contraceptives may be less reliable; use an additional method.

Contraindications

• Allergy to Saquinavir or Ritonavir.
• Inborn or acquired long QT interval, a known heart rhythm problem, a very slow heart rate or uncorrected low potassium or magnesium.
• Severe liver disease.
• Use with any of the interacting medicines listed above that must not be combined.

Side Effects

Common side effects include nausea, diarrhoea, stomach pain, bloating, tiredness, headache and changes in blood fats or blood sugar. Some people notice changes in body fat distribution or skin rash.

Less common but serious effects include heart rhythm changes (QT or PR prolongation), liver problems, new or worse diabetes, and increased bleeding in people with haemophilia.

Get urgent medical help if you have fainting, a fast or irregular heartbeat, palpitations, severe dizziness, yellowing of the skin or eyes, severe stomach pain, or a severe rash with blisters or swelling of the face.

Pregnancy and Lactation

HIV treatment in pregnancy is important to protect the baby, but Saquinavir is not a preferred choice and should only be used if your HIV doctor decides it is suitable. Tell your doctor at once if you are pregnant or planning a pregnancy. HIV can pass to a baby through breast milk, so follow your doctor's advice about feeding your baby.

Precautions and Warnings

• Your doctor will usually check an ECG (heart tracing) before and during treatment.
• Use with care in liver disease, including hepatitis B or C, and in diabetes or haemophilia.
• Blood tests for viral load, CD4 count, liver function, blood sugar and blood fats are needed regularly.
• As the immune system recovers, old hidden infections may flare up; report any new symptoms.
• Do not change or stop your HIV medicines without speaking to your doctor.

Overdose

Taking too much may cause nausea, vomiting, stomach pain and dangerous heart rhythm changes. Contact a doctor or go to the nearest hospital straight away. Treatment is supportive with heart monitoring; there is no specific antidote.

Therapeutic Class

Antiretroviral, HIV protease inhibitor.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Keep in the original container.