View the Table: Some Drug Interactions with Drugs for IBD

Atovaquone (Mepron - Burroughs Wellcome), a hydroxynaphthoquinone, was recently approved by the US Food and Drug Administration (FDA) for oral treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in patients who cannot tolerate trimethoprim-sulfamethoxazole (Septra, Bactrim, and others). PCP is a common opportunistic infection and frequent cause of death in patients with AIDS.

Previously approved by the FDA for treatment of depression, general anxiety disorder, diabetic peripheral neuropathic pain and fibromyalgia, duloxetine (Cymbalta – Lilly) has now also been approved for treatment of chronic musculoskeletal pain.

The FDA has approved ivacaftor (eye va kaf’ tor; Kalydeco – Vertex) for oral treatment of cystic fibrosis (CF) in patients ≥6 years old with the G551D mutation, which is found in about 5% of patients with CF. It is the first drug approved in the US that treats the cause of the disease.

The FDA has approved vorasidenib (Voranigo – Servier), an oral isocitrate dehydrogenase (IDH) inhibitor, for treatment of grade 2 astrocytoma or oligodendroglioma in patients ≥12 years old with an IDH1 or IDH2 mutation. It is the first systemic treatment to be approved in the US for this indication.

The drugs of choice for treatment of fungal infections are listed in the table that begins on page 62. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines for some of these infections are available online from the Infectious Diseases Society of America (www.idsociety.org).

The FDA has approved an IV formulation of the antifungal drug posaconazole (Noxafil - Merck) for prophylaxis of Aspergillus and Candida infections in adults at high risk for these infections, such as those with prolonged neutropenia. Posaconazole is also available as delayed-release tablets and an oral suspension.With activity against Aspergillus and Candida, posaconazole has an antifungal spectrum similar to that of voriconazole (Vfend, and generics), but unlike voriconazole it is also active against many species of Mucorales (formerly called Zygomycetes), such as Mucor and Rhizopus....

Olmesartan medoxomil (Benicar - Sankyo), a substituted imidazole, is the seventh oral angiotensin II receptor blocker (ARB) approved by the FDA for treatment of hypertension.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

The FDA has approved oral and injectable formulations of the HIV-1 capsid inhibitor lenacapavir (Sunlenca – Gilead) for use with other antiretroviral drugs to treat multidrug-resistant HIV-1 infection (MDR-HIV) in heavily treatment-experienced adults whose current regimen is failing. Lenacapavir is the third drug to be approved exclusively for treatment of MDR-HIV; the intravenously administered CD4-directed antibody ibalizumab-uiyk (Trogarzo) and the orally administered HIV-1 gp120-directed attachment inhibitor fostemsavir (Rukobia) were approved earlier.