Lactulose is a non-absorbable sugar used in the treatment of constipation and hepatic encephalopathy. It is a disaccharide (double-sugar) formed from one molecule each of the simple sugars (monosaccharides) fructose and galactose. Lactulose is not normally present in raw milk but is a product of heat-processed: the greater the heat, the greater amount of this substance. Lactulose is not absorbed in the small intestine nor broken down by human enzymes, thus stays in the digestive bolus through most of its course, causing retention of water through osmosis leading to softer, easier to pass stool. It has a secondary laxative effect in the colon, where it is fermented by the gut flora, producing metabolites which have osmotic powers and peristalsis-stimulating effects (such as acetate), but also methane associated with flatulence. Lactulose is metabolized in the colon by bacterial flora to short chain fatty acids including lactic acid and acetic acid. These partially dissociate, acidifying the colonic contents (increasing the H+ concentration in the gut).[14] This favors the formation of the nonabsorbable NH+4 from NH3, trapping NH3 in the colon and effectively reducing plasma NH3 concentrations. Lactulose is used in the treatment of chronic constipation in patients of all ages as a long-term treatment. Lactulose is used for chronic idiopathic constipation, i.e. chronic constipation occurring without any identifiable cause. Lactulose may be used to counter the constipating effects of opioids, and in the symptomatic treatment of hemorrhoids as a stool softener.

Diazepam is a benzodiazepine first discovered at Hoffman-La Roche in the late 1950s. Diazepam was approved by FDA for the treatment of anxiety disorders as well as for such conditions as skeletal muscle spasm, alcohol withdrawal syndrom and convulsions (under the most known brand Valium). The drug acts by binding to GABA-A receptors and potentiating GABA evoked current. Chronic diazepam use is associated with tolerance, dependence, and withdrawal.

Amitriptyline is a derivative of dibenzocycloheptadiene and a tricyclic antidepressant (TCA) and is mainly used to treat symptoms of depression. It works on the central nervous system (CNS) by inhibiting the membrane pump mechanism responsible for uptake of norepinephrine and serotonin in adrenergic and serotonergic neurons. Amitriptyline has been frequently used as an active comparator in clinical trials on newer antidepressants. It is rarely used as a first-line antidepressant nowadays due to its high degree of toxicity in overdose and generally poorer tolerability than the newer antidepressants.

Cyclizine (cyclizine hydrochloride, Valoid®) is a histamine H1 antagonist of the piperazine class which is characterised by a low incidence of drowsiness. It possesses anticholinergic and antiemetic properties. The exact mechanism by which cyclizin (cyclizine hydrochloride, Valoid®) can prevent or suppress both nausea and vomiting from various causes is unknown. It increases lower oesophageal sphincter tone and reduces the sensitivity of the labyrinthine apparatus. It may inhibit the part of the midbrain known collectively as the emetic centre.

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.

Cyclizine (cyclizine hydrochloride, Valoid®) is a histamine H1 antagonist of the piperazine class which is characterised by a low incidence of drowsiness. It possesses anticholinergic and antiemetic properties. The exact mechanism by which cyclizin (cyclizine hydrochloride, Valoid®) can prevent or suppress both nausea and vomiting from various causes is unknown. It increases lower oesophageal sphincter tone and reduces the sensitivity of the labyrinthine apparatus. It may inhibit the part of the midbrain known collectively as the emetic centre.

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.