Purinol

Mercaptopurine results from biotransformation of the inactive precursor azathioprine (p. 37). The uricostatic allo-purinol inhibits the degradation of 6-mercaptopurine such that co-adminis-tration of the two drugs permits dose reduction of the latter. 

Compendial Monograph Evaluation and Development Allo-purinol, PharmacopeialForum, 3952 (1984). 

Proprietary Names. Alloprin Allopur Aluline Apurin Cap-lenal Capurate Cosuric Foligan Lopurin Progout Purinol Uriscel Zyloprim Zyloric. 

Many drugs have been associated with corneal and crystalline lens opacities, including phenothiazines, allo-purinol, phenytoin, diuretics, and heavy alcohol consmnp-tion. Over 16 drugs are listed to be associated with epithelial vortex keratopathy alone in a recent review, whereas the stroma is affected much less frequently. A variety of ocular toxicities are well recognized, aside from isolated case reports, and the drugs responsible for these side effects are listed in Table 35-2. 

K3. Eielley, W. N., and Wyngaaiden, J. B., Effect of dietary piudne restriction, allo-purinol, and oxipurinol on urinary excretion of ultraviolet-absorbing compoimds. Clin. Chem. 16, 707-713 (1970). 

Bodalbhai and Brajter-Toth [655] undertook a closer investigation of the effect of electrode treatment on small adsorbing biological molecules, such as 2,6-dia-mino-8-purinol (DAPOL), in order to .shed light on the relative importance of. . . adsorption in their electrochemical behavior. On the basis of effects such as the pH dependence of adsorption rate, they concluded that the chemistry of the surface may be important. ... 

Esfandiarpour I, Alavi A. Evaluating the efficacy of aUo-purinol and meglumine antimoniate (Glucantime) in the treatment of cutaneous leishmaniasis. Int J Dermatol 2002 41(8) 521. ... 

Jahnehen E, Meinertz I, Gilfrich HJ. Interaction of allo-purinol with phenprocoumon in man. Klin Wochenschr 1977 55(15) 759-61. 

The risk of rashes caused by aminopeniciUins does not seem to be increased by parallel treatment with aUo-purinol (243), as had been suggested before (244). 

The tolerated dose varies with the individual patient. Allo-purinol potentiates the effect of mercaptopurine by inhibiting its metabolism. It also increases its toxicity, however. If allo-purinol is given for potentiation or reduction of hyperuricemia resulting from the killing of leukemia cells, the doses of mercaptopurine must be decreased. ... 

Trade names Alio 300 Allo-Puren Alloprin Atisuril Bleminol Caplenal Hamarin Novo-Purol Purinol Unizuric Zyloprim (Prometheus) Zyloric Indications Gouty arthritis... 

Caplenal, Hamarin, Novo-Purol, Purinol, Unizuric, Ametycine mitomycin... 

Currently, allopurinol is the only drug approved for use in inhibiting uric acid synthesis. Both allopurinol and its major metabolite, oxy-purinol, are xanthine oxidase inhibitors and thus impair the conversion of hypoxanthine to xanthine and xanthine to uric acid. Allopurinol also lowers the intracellular concentration of PRPP. Because of the long half-life of its metabolite, allopurinol can be given once daily. An oral daily dose of 300 mg usually is sufficient. Occasionally, as much as 600 to 800 mg/day may be necessary. 

In this section are described the important chemical features of those substrates which are oxidized by the molybdenum hydroxylases. Although these enzymes, particularly aldehyde oxidase, also catalyse numerous reductive reactions under anaerobic conditions in vitro, it has not yet been established whether they occur under physiological conditions and there are as yet insufficient examples of any one reduction reaction to permit any conclusions regarding the structure of substrates. Thus, such reactions will not be discussed here (see [11] and references therein). Properties of those inhibitors which bind at the Mo centre and are also substrate analogues will also be included. However, the interaction of inhibitors such as cyanide and arsenite with the molybdenum hydroxylases and the mechanism of action of the specific xanthine oxidase inhibitor, allo-purinol, have been comprehensively described elsewhere [8, 12, 14, 157]. 

Reiter S, Simminds HA, Zollner N, Braun SL and Knedel M (1990) Demonstration of a combined deficiency of xanthine oxidase and aldehyde oxidase in xanthinuric patients not forming oxy-purinol. Clin Chirn Acta 187 221—234. 

The products are ohgomeric to high polymers with DP values ranging from 10 to 1,000. Yields ranged from about 10 to over 90%. A wide range of diamines were employed including simple aliphatic diamines such as 1,6-diaminohexane, simple aromatic diamines such as p-phenylenediamine, to more complex diamines such as adenine, 2,6-diamino-8-purinol, 4,4 -diaminodiphenylsulfon, Zineb, and 2,4-diamino-5(3,4-dimethoxybenzil)pyrimidine. 

Hamaguchi Y, Fujimoto M, Enokido Y, Wayaku T, Kaji K, Echigo T, Takehara K. Intractable genital ulcers from herpes simplex virus reactivation in drug-induced hypersensitivity syndrome caused by allo-purinol. Int J Dermatol 2010 49(6) 700-4. 

The excretion of uric acid in the urine under various experimental conditions is displayed in Fig. 2. The open bars show the excretion of uric acid in the control group receiving allantoxan-amide alone. In the collection period of 1 - 6 hours, there was no major difference in uric acid excretion between control group and rats having simultaneously received allantoxanamide and allo-purinol in doses of 10, 25, 50 and 100 mg/kg. 

Uric acid, hypoxanthine, xanthine, allopurinol, oxi-purinol and allopurinol-1-riboside by a modification of the method of Webster et al. on a Chrompack RP-8 column. Urine samples were preseparated on anion-exchange columns. For the determination of oxipurinol-7-riboside a preextraction of ribosides on Bio-Rad Affi-Gel 601 was necessary. For the determination of adenine the mobile phase contained 20% of methanol and was adjusted to pH 5.5. ... 

Excretion of purine into the gut in the presence of allo-purinol has been demonstrated, but block of purine absorption by allopurinol has not been excluded. 

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