Fourteen states in the US - Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Jersey, New Mexico, Oregon, Rhode Island, Vermont and Washington - now permit, or soon will permit, some medical use of marijuana (Cannabis sativa). In some states, licensed facilities dispense botanical cannabis by prescription. In others, limited self-cultivation is permitted for medical use.

The FDA has approved tenapanor (Ibsrela - Ardelyx), a sodium/hydrogen exchanger 3 (NHE3) inhibitor, for twice-daily oral treatment of irritable bowel syndrome with constipation (IBS-C) in adults. Tenapanor is the first NHE3 inhibitor to become available in the US.

Sumatriptan (soo ma trip' tan; Imitrex - Glaxo), a serotonin (5-HT) agonist, is now available in Canada and may soon be available in the USA for oral or parenteral treatment of migraine headache. The parenteral formulation is designed for patients to inject themselves subcutaneously. Sumatriptan is not recommended for prophylactic use.

Tramadol hydrochloride (Ultram - Ortho-McNeil), a centrally-acting analgesic marketed in Germany since 1977, was recently approved by the US Food and Drug Administration for oral treatment of moderate to moderately severe pain. Despite some opioid activity, tramadol has not been scheduled as a controlled substance.

The FDA has approved two new drugs for sickle cell disease: crizanlizumab-tmca (Adakveo – Novartis), an IV P-selectin blocker, and voxelotor (Oxbryta – GBT), an oral hemoglobin S (HbS) polymerization inhibitor.

Cannabis (marijuana) contains more than 60 pharmacologically active cannabinoids; delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best known. THC is the main psychoactive constituent of cannabis. CBD, unlike THC, does not produce intoxication or euphoria.

A new once-daily formulation of gabapentin (Gralise – Depomed) has been approved by the FDA for treatment of postherpetic neuralgia (PHN). Immediate-release (IR) gabapentin (Neurontin, and others), which has been available in the US since 1994, is also approved for this indication, but is taken three times a day. Extended-release gabapentin enacarbil (Horizant) was recently approved by the FDA for treatment of restless legs syndrome.

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.

The FDA has approved Xtampza ER (Collegium), a new extended-release, abuse-deterrent capsule formulation of oxycodone, for management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.