Orphenadrine is an anticholinergic drug of the ethanolamine antihistamine class used to treat muscle pain and to help with motor control in Parkinson's disease but has largely been superseded by newer drugs. Orphenadrine binds and inhibits both histamine H1 receptors and NMDA receptors. It restores the motor disturbances induced by neuroleptics, in particular, the hyperkinesia. The dopamine deficiency in the striatum increases the stimulating effects of the cholinergic system. This stimulation is counteracted by the anticholinergic effect of orphenadrine. It may have a relaxing effect on skeletal muscle spasms and it has a mood elevating effect. Orphenadrine is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute painful musculoskeletal conditions. Orphenadrine is an anticholinergic with a predominantly central effect and only a weak peripheral effect. In addition, it has mild antihistaminic and local anesthetic properties. Parkinson's syndrome is the consequence of a disturbed balance between cholinergic and dopaminergic neurotransmission in the basal ganglia caused by a decrease in dopamine. Orphenadrine restores the physiological equilibrium and has a favorable effect on the rigidity and tremor of Parkinson's disease and Parkinsonian syndromes. Adverse reactions of orphenadrine citrate are mainly due to the mild anticholinergic action of orphenadrine citrate and are usually associated with higher dosage. Dryness of the mouth is usually the first adverse effect to appear. When the daily dose is increased, possible adverse effects include tachycardia, palpitation, urinary hesitancy or retention, blurred vision, dilatation of pupils, increased ocular tension, weakness, nausea, vomiting, headache, dizziness, constipation, drowsiness, hypersensitivity reactions, pruritus, hallucinations, agitation, tremor, gastric irritation and rarely urticaria and other dermatoses

Dimethyl maleate is an organic compound, the (Z)-isomer of the dimethyl ester of fumaric acid. Dimethyl maleate can be synthesized from maleic anhydride and methanol, with sulfuric acid acting as acid catalyst, via a nucleophilic acyl substitution for the monomethyl ester, followed by a Fischer esterification reaction for the dimethyl ester. Dimethyl maleate is used in many organic syntheses as a dienophile for diene synthesis. It is used as an additive and intermediate for plastics, pigments, pharmaceuticals, and agricultural products. It is also an intermediate for the production of paints, adhesives, and copolymers.

Meclizine, a piperazine-derivative H1-receptor antagonist similar to buclizine, cyclizine, and hydroxyzine, is used as an antivertigo/antiemetic agent. Meclizine is used in the management of nausea, vomiting, and dizziness associated with motion sickness and vertigo in diseases affecting the vestibular apparatus. Along with its actions as an antagonist at H1-receptors, meclizine also possesses anticholinergic, central nervous system depressant, and local anesthetic effects. Meclizine depresses labyrinth excitability and vestibular stimulation and may affect the medullary chemoreceptor trigger zone. It is sold under the brand names Bonine, Bonamine, Antivert, Postafen, Sea Legs, and Dramamine II.

Diphenhydramine is an antihistamine which is used in the combination with naproxen sodium for the relief of occasional sleeplessness when associated with minor aches and pains. Diphenhydramine has a role nighttime sleep-aid and naproxen sodium is a pain reliever. In addition, diphenhydramine used in relieving symptoms in patients with moderate-to-severe seasonal allergic rhinitis. Diphenhydramine acts as an antagonist of histamine H1 receptor. Besides, was shown potential to repurpose diphenhydramine as an anti-melanoma therapeutic agent, it induces melanoma cell apoptosis by suppressing STAT3/MCL-1 survival signaling pathway.

Diphenhydramine is an antihistamine which is used in the combination with naproxen sodium for the relief of occasional sleeplessness when associated with minor aches and pains. Diphenhydramine has a role nighttime sleep-aid and naproxen sodium is a pain reliever. In addition, diphenhydramine used in relieving symptoms in patients with moderate-to-severe seasonal allergic rhinitis. Diphenhydramine acts as an antagonist of histamine H1 receptor. Besides, was shown potential to repurpose diphenhydramine as an anti-melanoma therapeutic agent, it induces melanoma cell apoptosis by suppressing STAT3/MCL-1 survival signaling pathway.