An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. Papaverine is a vasodilating agent. Papaverine is used for the treating certain conditions that are accompanied by smooth muscle spasms (eg, blood vessel, urinary, gallbladder, or intestinal spasm). Papaverine is a nonxanthine phosphodiesterase inhibitor for the relief of cerebral and peripheral ischemia associated with arterial spasm and myocardial ischemia complicated by arrhythmias. The main actions of Papaverine are exerted on cardiac and smooth muscle. Like qathidine, Papaverine acts directly on the heart muscle to depress conduction and prolong the refractory period. Papaverine relaxes various smooth muscles. This relaxation may be prominent if spasm exists. The muscle cell is not paralyzed by Papaverine and still responds to drugs and other stimuli causing contraction. The antispasmodic effect is a direct one, and unrelated to muscle innervation. Papaverine is practically devoid of effects on the central nervous system. Papaverine relaxes the smooth musculature of the larger blood vessels, especially coronary, systemic peripheral, and pulmonary arteries. Papaverine is a potent, specific inhibitor of PDE10A. Papaverine for treatment of erectile dysfunction (ED) is excluded from coverage.

Oral dehydroemetine dihydrochloride (+/-) (Mebadin) was found useful both as a tissue and contact amoebicide. It is much less toxic and more active than emetine and can be given in larger doses and for longer periods with safety. Owing to the quick excretion, repeat courses can be given at short intervals, as necessary, without danger. No serious side effects were noted particularly with the oral form and it was far better tolerated by children, who received relatively higher dosage than most adults. The only contra-indication is for patients with manifest decompensation of vital organs, or fevers. Mebadin injection and Mebadin tablets are discontinued products.

Alcuronium (diallylnortoxiferine) is a semi-synthetic substance prepared from C-toxiferine I a bis-quaternary alkaloid obtained from Strychnos toxifera. Alcuronium is a neuromuscular blocking (NMB) agent, alternatively referred to as a skeletal muscle relaxant. Alcuronium is used for endotracheal intubation and to produce muscle relaxation in general anesthesia during surgical procedures. The pharmacological action of alcuronium is readily reversed by neostigmine, and it produced little histamine release. The major disadvantage of alcuronium is that it elicits a vagolytic effect produced by a selective atropine-like blockade of cardiac muscarinic receptors.

Stibogluconic acid (Sodium stibogluconate) is the pentavalent antimonial compound used to treat leishmaniasis and is only available for administration by injection. Sodium stibogluconate is sold in the UK as Pentostam (manufactured by GlaxoSmithKline). Sodium stibogluconate was granted orphan drug designation for the treatment of cutaneous leishmaniasis by the US FDA in January 2007. It is available in the United States only through the Centers for Disease Control. Sodium stibogluconate is indicated for the treatment of various types of a protozoal infection called leishmaniasis, which may result from sandfly bites in tropical and temperate parts of the world. It is also investigated for use/treatment in cancer. The mode of action of sodium stibogluconate is not clearly understood. In vitro exposure of amastigotes to 500 mg pentavalent antimony/ml results in a greater than 50% decrease in parasite DNA, RNA protein and purine nucleoside triphosphate levels. It has been postulated that the reduction in ATP (adenosine triphosphate) and GTP (guanosine triphosphate) synthesis contributes to decreased macromolecular synthesis. Sodium stibogluconate was shown to specifically inhibit type I DNA topoisomerase from Leishmania donovani through the inhibition of the unwinding and cleavage of the supercoiled plasmid pBR322, and to stabilize topoisomerase and DNA covalent complexes but not calf-thymus topoisomerase I and Escherichia coli DNA gyrase. Sodium stibogluconate is also a potent inhibitor of PTPases Src homology PTPase1 (SHP-1), SHP-2, and PTP1B but not the dual-specificity phosphatase mitogen-activated protein kinase phosphatase 1. Sodium stibogluconate combined with IFN-alpha-2b (IFN-α) inhibited solid tumor cell line growth in vitro, in vivo it was well tolerated and augmented cellular immune parameters.

Diloxanide (used in the form of furoate) was developed for the treatment of intestinal amoebiasis. The effectiveness of the drug was proved in clinical trials, however, the mechanism of its action is unknown. The drug is not marketed in the United States, athough it is available in India.

Bleomycin sulfate is an antineoplastic antibiotic isolated from Streptomyces verticillus. It is a mixture of glycopeptide antibiotics containing primarily Bleomycin A2 (~70%) and B2 (~30%). Bleomycin binds to DNA, inhibits DNA synthesis, and causes single strand scission of DNA in vivo and in vitro at specific base sequences.

Bleomycin sulfate is an antineoplastic antibiotic isolated from Streptomyces verticillus. It is a mixture of glycopeptide antibiotics containing primarily Bleomycin A2 (~70%) and B2 (~30%). Bleomycin binds to DNA, inhibits DNA synthesis, and causes single strand scission of DNA in vivo and in vitro at specific base sequences.

Clomiphene (CLOMID®) is a triphenyl ethylene stilbene derivative which is an estrogen agonist or antagonist depending on the target tissue. It is an orally administered, nonsteroidal, ovulatory stimulant. Clomiphene (CLOMID®) is a mixture of two geometric isomers [cis (zuclomiphene) and trans (enclomiphene)] containing between 30% and 50% of the cis-isomer. Clomiphene (CLOMID®) initiates a series of endocrine events culminating in a preovulatory gonadotropin surge and subsequent follicular rupture. The first endocrine event in response to a course of clomiphene therapy is an increase in the release of pituitary gonadotropins. This initiates steroidogenesis and folliculogenesis, resulting in growth of the ovarian follicle and an increase in the circulating level of estradiol. Following ovulation, plasma progesterone and estradiol rise and fall as they would in a normal ovulatory cycle.

Neomycin is an aminoglycoside antibiotic found in many topical medications such as creams, ointments, and eye drops. In vitro tests have demonstrated that neomycin is bactericidal and acts by inhibiting the synthesis of protein in susceptible bacterial cells. It is effective primarily against gram-negative bacilli but does have some activity against gram-positive organisms. Neomycin is active in vitro against Escherichia coli and the Klebsiella-Entero. Topical uses include treatment for superficial eye infections caused by susceptible bacteria (used in combination with other anti-infective), treatment of otitis externa caused by susceptible bacteria, treatment or prevention of bacterial infections in skin lesions, and use as a continuous short-term irrigant or rinse to prevent bacteriuria and gram negative rod bacteremia in bacteriuria patients with indwelling catheters. May be used orally to treat hepatic encephalopathy, as a perioperative prophylactic agent, and as an adjunct to fluid and electrolyte replacement in the treatment of diarrhea caused to enter pathogenic E. coli (EPEC). Neomycin sulfate has been shown to be effective adjunctive therapy in hepatic coma by reduction of the ammonia forming bacteria in the intestinal tract. The subsequent reduction in blood ammonia has resulted in neurologic improvement. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Neomycin Sulfate Oral Solution and other antibacterial drugs, susceptible bacteria should use Neomycin Sulfate Oral Solution only to treat or prevent infections that are proven or strongly suspected to be caused. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Neomycin binds to four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site near nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes