The FDA has approved erenumab-aooe (Aimovig – Amgen/Novartis), a once-monthly, subcutaneously-injected, monoclonal antibody against the calcitonin gene-related peptide receptor, for preventive treatment of migraine in adults. It is the first drug in its class to be approved by the FDA.

The FDA recently cleared the AmpliChip CYP450 Test (Roche), which analyzes blood-derived DNA to detect genetic variations in the activity of cytochrome P450 (CYP) enzymes CYP2D6 and CYP2C19 and determines the metabolizer status of the patient. The test is intended to help guide clinicians in prescribing individualized drug therapy. About 25% of all drugs, including many antidepressants and antipsychotics, are substrates of either CYP2D6 or CYP2C19. The test is being promoted initially to psychiatrists.

The physiologic changes that occur with aging can affect the pharmacokinetics and pharmacodynamics of many prescription and over-the-counter drugs, increasing the likelihood of adverse effects.

Duloxetine (Cymbalta - Lilly) is the second drug to be approved by the FDA for treatment of fibromyalgia. Pregabalin (Lyrica), which is also approved for treatment of neuropathic pain and epilepsy, was the first. Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) that is already marketed for treatment of depression and diabetic neuropathy.

Patients with frequent, severe or disabling migraine headaches may benefit from taking a drug to prevent the attacks. Beta-blockers traditionally have been the prophylactic treatment of choice, but in recent years some antiepileptic drugs such as valproate (Depakote, and others) and topiramate (Topamax) have also been used for this indication. Valproate was approved by the FDA for such use in 1996. Now topiramate has also been approved.

The FDA has approved two subcutaneously injected calcitonin gene-related peptide (CGRP) antagonists, fremanezumab-vfrm (Ajovy – Teva) and galcanezumab-gnlm (Emgality – Lilly), for migraine prevention in adults. Fremanezumab and galcanezumab are the second and third subcutaneously injected monoclonal antibodies that target the CGRP pathway to be approved by the FDA for this indication; erenumab-aooe (Aimovig), which targets the CGRP receptor, was the first.

The FDA has approved eptinezumab-jjmr (Vyepti – Lundbeck), a calcitonin gene-related peptide (CGRP) antagonist administered IV once every 3 months, for migraine prevention in adults. It is the fourth monoclonal antibody to be approved for this indication; erenumab (Aimovig), fremanezumab (Ajovy), and galcanezumab (Emgality), which are all given subcutaneously once monthly (fremanezumab can also be given once every 3 months), were approved earlier.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Pregabalin (Lyrica - Pfizer) is the first drug approved by the FDA for management of fibromyalgia. When it was first marketed, pregabalin, which is structurally similar to gabapentin (Neurontin, and others), was approved for treatment of neuropathic pain associated with postherpetic neuralgia and diabetic peripheral neuropathy and for adjunctive treatment of partial onset seizures in adults with epilepsy. It has also been prescribed off-label for other types of neuropathic pain such as sciatica.

Milnacipran (Savella - Forest), an oral selective serotonin and norepinephrine reuptake inhibitor (SNRI), is the third drug approved by the FDA for management of fibromyalgia. The 2 others are pregabalin, a gammaaminobutyric acid (GABA) analog also approved for treatment of diabetic neuropathy, post-herpetic neuralgia and epilepsy, and duloxetine, an SNRI also approved for treatment of depression, diabetic neuropathy and generalized anxiety disorder.