FDA approves avanafil and tafluprost
Safety. The most common adverse reactions (≥2%) observed in subjects during the three placebo-controlled clinical trials of avanafil included headache, flushing, nasal congestion, nasopharyngitis, and back pain. Patients receiving avanafil for an additional 40 weeks during a long-term safety study did not experience worsening of adverse effects over time. The use of avanafil along with antihypertensive agents, particularly alpha-blockers, or substantial amounts of alcohol (>3 units) may lead to hypotension. Like all PDE5 inhibitors, patient taking avanafil may rarely develop a sudden decrease or loss of hearing, accompanied by tinnitus or dizziness, or non-arteritic anterior ischemic optic neuropathy.
Dosage. The recommended dose of avanafil for most patients is 100 mg taken with or without food approximately 30 minutes before sexual activity on an as-needed basis, but no more than once daily. The dose of avanafil may be increased to 200 mg or decreased to 50 mg based on efficacy and/or tolerability, with the preferred dose being the lowest providing benefit. No dosage adjustment in mild-to-moderate renal dysfunction is required. Avanafil should not be used in patients taking a nitrate or a strong CYP3A4 inhibitor, and no more than 50 mg in a 24-hour period should be used in patients concomitantly taking a moderate CYP3A4 inhibitor or a stable dose of an alpha-blocker. Avanafil should not be used when sexual activity is inadvisable because of cardiovascular or other reasons.
Tafluprost ophthalmic solution
Open-angle glaucoma is the most common type of glaucoma, accounting for at least 90% of all cases, and affecting about 3 million Americans. On February 10, FDA approved tafluprost (Zioptan, Merck) ophthalmic solution 0.0015% to reduce elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. Tafluprost (acid) is a prostaglandin analog, which is believed to reduce IOP by increasing uveoscleral outflow of aqueous humor.
Efficacy. Tafluprost ophthalmic solution 0.0015% was evaluated in five controlled clinical studies of up to 24 months duration. In study subjects with open-angle glaucoma or ocular hypertension, baseline pressures of 23 to 26 mmHg, and treated with tafluprost dosed once daily in the evening, reductions in IOP at 3 and 6 months of 6 mmHg to 8 mmHg and 5 mmHg to 8 mmHg, respectively, were observed.
Safety. The safety of tafluprost ophthalmic solution 0.0015% was evaluated in 905 patients during the five controlled clinical studies. The most common adverse reaction observed in patients treated with tafluprost was conjunctival hyperemia, which was reported in between 4% and 20% of study subjects. Other ocular adverse reactions reported in at least 2% of subjects during clinical trials included: ocular stinging/irritation (7%), ocular pruritus including allergic conjunctivitis (5%), cataracts (3%), dry eye (3%), ocular pain (3%), eyelash darkening (2%), growth of eyelashes (2%), and blurry vision (2%). Of note, brown pigmentation of the iris and periorbital tissue (eyelid) can also occur and may be permanent, but is not typically noticeable for months to years after drug initiation.
Dosage. The recommended dose is 1 drop of tafluprost ophthalmic solution 0.0015% in the conjunctival sac of the affected eye(s) once daily each evening. The dose of tafluprost should not exceed once daily since it has been shown that more frequent administration of prostaglandin analogs may lessen the IOP-lowering effect. Tafluprost ophthalmic may be used concomitantly with other topical ophthalmic drugs to lower IOP; however, each one should be administered at least 5 minutes apart.
Craig I. Coleman is associate professor of Pharmacy Practice, University of Connecticut School of Pharmacy, Storrs, Conn., and director of the Pharmacoeconomics and Outcomes Studies Group, Hartford Hospital.