Verapamil is a FDA approved drug used to treat high blood pressure and to control chest pain. Verapamil is an L-type calcium channel blocker that also has antiarrythmic activity. The R-enantiomer is more effective at reducing blood pressure compared to the S-enantiomer. However, the S-enantiomer is 20 times more potent than the R-enantiomer at prolonging the PR interval in treating arrhythmias. Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known.

Clocortolone (used in form of pivalate prodrug) is a topical glucocorticoid that was approved by FDA for the treatment of corticosteroid-responsive skin disorders. The drug exerts its anti-inflammatory action by binding to glucocorticoid receptor which results in regulation of the expression of proinflammatory cytokines and further antiproliferative, immunosuppressive, and initial vasoconstrictive effects.

Desonide is a topical glucocorticoid which was approved by FDA for the treatment of such conditions as eczema, psoriasis, atopic dermatitis, etc. The exact mechanism of drug action is unknown.

Fentanyl is a potent agonist of mu opioid receptor. It is used to relieve severe pain, such as after surgery or during cancer treatment, and breakthrough pain (flare-ups of intense pain despite round-the-clock narcotic treatment). Fentanyl is an extremely powerful analgesic, 50–100-times more potent than morphine. Fentanyl harbors massive risk for addiction and abuse regardless of its prescription form. Fentanyl abuse is especially dangerous to those without a tolerance to opioids. The substance’s already elevated risk of overdose is multiplied when someone without a tolerance abuses it.

Fluorometholone is a glucocorticoid employed, usually as eye drops, in the treatment of allergic and inflammatory conditions of the eye. Corticosteroids such as fluorometholone inhibit the inflammatory response to a variety of inciting agents and probably delay or slow healing. There is no generally accepted explanation for the mechanism of action of ocular corticosteroids. However, corticosteroids are thought to act by the induction of phospholipase A2 inhibitory proteins, collectively called lipocortins. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor, arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A2. Corticosteroids are capable of producing a rise in intraocular pressure. In clinical studies of documented steroid-responders, fluorometholone demonstrated a significantly longer average time to produce a rise in intraocular pressure than dexamethasone phosphate.

Oxymorphone is an analgesic that is FDA approved for the treatment of moderate to severe pain. It is also indicated for relief of anxiety in patients with dyspnea associated with pulmonary edema secondary to acute left ventricular dysfunction. Oxymorphone (brand names Opana, Numorphan, Numorphone) is a full opioid agonist and is relatively selective for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. Adverse reactions (≥ 2% of patients): seen with the immediate release tablet formulation Nausea, pyrexia, somnolence, vomiting, pruritus, headache, dizziness, constipation, and confusion. Concomitant use with serotonergic drugs may result in serotonin syndrome. Avoid use of mixed agonist/antagonist and partial agonist opioid analgesics with Opana because they may reduce analgesic effect of Opana or precipitate withdrawal symptoms.

Dexamethasone is an anti-inflammatory agent that is FDA approved for the treatment of many conditions, including rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive lung disease, croup, brain swelling and others. Dexamethasone is a glucocorticoid agonist. Unbound dexamethasone crosses cell membranes and binds with high affinity to specific cytoplasmic glucocorticoid receptors. Adverse reactions are: Glaucoma with optic nerve damage, visual acuity and field defects; cataract formation; secondary ocular infection following suppression of host response; and perforation of the globe may occur; muscle weakness; osteoporosis and others. Aminoglutethimide may diminish adrenal suppression by corticosteroids. Macrolide antibiotics have been reported to cause a significant decrease in corticosteroid clearance.

Levorphanol, brand name Levo-Dromoran, is an opioid medication used to treat moderate to severe pain. Levorphanol is indicated for the management of moderate to severe pain where an opioid analgesic is appropriate. It is a potent synthetic opioid mu-receptor agonist similar in action to morphine. Like other opioid mu-receptor agonists, it is believed to act at receptors in both the brain and spinal cord to alter the transmission and perception of pain. The onset and peak analgesic effects following administration of levorphanol are similar to morphine when administered at equal analgesic doses. Levorphanol produces a degree of respiratory depression similar to that produced by morphine at equal analgesic doses, and like many opioid mu-receptor agonists, levorphanol produces euphoria or has a positive effect on mood in many individuals.

Oxycodone is a semisynthetic opioid used for the management of acute and chronic pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Oxycodone is a highly selective full agonist of the μ-opioid receptor (MOR), with low affinity for the δ-opioid receptor (DOR) and κ-opioid receptor (KOR). After oxycodone binds to the MOR, a G protein-complex is released, which inhibits the release of neurotransmitters by the cell by reducing the amount of cAMP produced, closing calcium channels, and opening potassium channels. After a dose of conventional (instant-release) oral oxycodone, the onset of action is 10–30 minutes, and peak plasma levels of the drug are attained within roughly 30–60 minutes in contrast, after a dose of OxyContin (an oral controlled-release formulation), peak plasma levels of oxycodone occur in about three hours. The duration of instant-release oxycodone is 3 to 6 hours, although this can be variable depending on the individual. Oxycodone in the blood is distributed to skeletal muscle, liver, intestinal tract, lungs, spleen, and brain. Serious side effects of oxycodone include reduced sensitivity to pain (beyond the pain the drug is taken to reduce), euphoria, anxiolysis, feelings of relaxation, and respiratory depression. Common side effects of oxycodone include constipation (23%), nausea (23%), vomiting (12%), somnolence (23%), dizziness (13%), itching (13%), dry mouth (6%), and sweating (5%).