The FDA has approved Gimoti (Evoke), a nasal spray formulation of the dopamine-2 (D₂) receptor antagonist metoclopramide, for relief of symptoms in adults with acute and recurrent diabetic gastroparesis. Metoclopramide (Reglan, and generics) has been available for years in conventional and orally-disintegrating tablets and in an injectable formulation. It is the only drug that is FDA-approved for treatment of diabetic gastroparesis.

An oral nonopioid analgesic is often sufficient for acute treatment of mild to moderate migraine pain without severe nausea or vomiting. A triptan is the drug of choice for treatment of moderate to severe migraine in most patients without vascular disease. Treatment of pain when it is still mild to moderate in intensity improves headache response and reduces the risk of recurrence.

The motor symptoms of Parkinson's disease (PD) are caused primarily by degeneration of dopaminergic neurons in the substantia nigra. The nonmotor symptoms of the disease are thought to be caused by degeneration of other neurotransmitter systems. No disease-modifying drugs are available for treatment of PD.

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.