Sildenafil oral suspension is a liquid formulation of the medication sildenafil. It is prescribed for individuals who have difficulty swallowing pills. This medication is primarily used to treat a specific form of high blood pressure that affects the arteries in the lungs and the right side of the heart. The liquid form is administered using an oral syringe for precise dosing.
Medical Uses for Sildenafil Oral Suspension
Sildenafil oral suspension is indicated for the treatment of pulmonary arterial hypertension (PAH) in adults. PAH is a condition characterized by high blood pressure within the blood vessels that supply the lungs. This increased pressure forces the heart, particularly the right ventricle, to work much harder to pump blood. The medication helps manage this condition by improving exercise ability and delaying the worsening of clinical symptoms.
The active ingredient, sildenafil, belongs to a class of drugs known as phosphodiesterase-5 (PDE5) inhibitors. As a PDE5 inhibitor, sildenafil works as a vasodilator, relaxing and widening the blood vessels in the lungs. This allows blood to flow more easily, which lowers the blood pressure within the pulmonary arteries and reduces the workload on the heart.
The brand name for sildenafil when prescribed for PAH is Revatio. Another brand, Viagra, is used to treat erectile dysfunction. While the active ingredient is the same, the dosage and purpose are different, and patients treated for PAH should not take other PDE5 inhibitors.
Proper Administration and Dosage
Proper administration is necessary for effectiveness. Before each use, the bottle must be shaken well for at least 10 seconds to ensure the medication is evenly mixed. Only the oral syringe provided with the medication should be used to measure the dose, as household spoons do not provide the needed accuracy. The medication can be taken with or without food.
Dosages are determined by a healthcare provider based on the patient’s medical condition and response to treatment. For adults with PAH, a common dosage is 20 milligrams (mg) taken three times a day, with doses spaced approximately 4 to 6 hours apart. Patients should not adjust their dose or stop taking the medication without consulting their care team.
If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. Doubling the dose can increase the risk of side effects.
Potential Side Effects and Safety Precautions
Patients using sildenafil oral suspension may experience side effects. Common effects include headaches, flushing, upset stomach, nosebleeds, and back or muscle pain. These reactions are generally mild and may decrease as the body adjusts. Dizziness and changes in vision, such as blurred vision or sensitivity to light, can also occur.
Some side effects are more serious and require immediate medical attention. Contact your healthcare provider right away if you experience:
- Sudden vision or hearing loss
- Chest pain, pressure, or an irregular heartbeat
- Shortness of breath or swelling in the hands and feet
- A painful erection lasting more than four hours (priapism)
Because it can cause dizziness or vision changes, patients should avoid driving or operating heavy machinery until they know how the drug affects them. Rise slowly from a sitting or lying position to reduce the risk of feeling lightheaded. Alcohol consumption should be avoided as it can increase dizziness.
Important Drug Interactions and Contraindications
Sildenafil can interact with other medications, which may alter its effects or increase the risk of adverse reactions. The most significant interaction is with nitrate drugs, often prescribed for chest pain (angina). Taking sildenafil with any form of nitrate, such as nitroglycerin, can cause a severe and dangerous drop in blood pressure.
Other medications can also interact with sildenafil, including alpha-blockers, certain antibiotics, antifungals, and other medicines that lower blood pressure. It is also contraindicated for use with riociguat, another medication for PAH, due to the increased risk of hypotension.
There are specific situations, known as contraindications, where sildenafil should not be used. It is contraindicated in patients with:
- A known hypersensitivity or allergy to sildenafil
- Severe heart or liver problems
- A history of specific eye diseases
- Pulmonary veno-occlusive disease (PVOD)
- Pulmonary hypertension secondary to sickle cell disease
Storage and Handling
Proper storage is important to maintain effectiveness. After being prepared by the pharmacist, the medication can be stored either at room temperature, below 30°C (86°F), or in a refrigerator between 2°C and 8°C (36°F and 46°F). Do not freeze the medication.
Keep the medication out of the reach of children and pets. The oral suspension has a limited shelf-life and any unused portion should be discarded after 60 days. Consult your pharmacist for guidance on how to safely dispose of expired or unused medication.