Theophylline

Theophylline

1,3-Dimethyl-3,7-dihydro-1H-purine-2,6-dione;1,3-dimethyl-xanthin;1H-Purine-2,6-dione, 3,7-dihydro-1,3-dimethyl-;3,7-dihydro-1,3-dimethyl-1h-purine-6-dione;3h)-dione,1,3-dimethyl-purine-6(1h;6-dione,3,7-dihydro-1,3-dimethyl-1H-Purine-2;accurbron;Acet-theocin

58-55-9

C7H8N4O2

ZFXYFBGIUFBOJW-UHFFFAOYSA-N

180.16

13463

200-385-7

TSCA listed

white

29395900

Respiratory Drugs

Appearance: white, crystalline powder, odorless, with a bitter taste. Solubility: freely soluble in solutions of alkali hydroxides and in ammonia; sparingly soluble in alcohol, in chloroform, and in ether; slightly soluble in water. Water solubility, 7.36g/L (20°C); density, 1.62g/cm3 ; melting point, 270–274°C; boiling point, 390.1°C (760 mmHg); flash point, 189.7°C; vapor pressure, 2.72E-06 mmHg (25°C).

1.3640 (rough estimate)

271-273 °C

312.97°C (rough estimate)

1.6700 (estimate)

8.3 g/L (20 ºC)

In acute overdoses, theophylline often causes severe emesis (75% in acute vs 30% in chronic). The emesis is often difficult to control with antiemetics. It is thought that theophylline causes increased gastric acid secretion and smooth muscle relaxation. Theophylline causes a release of endogenous catecholamines, and therefore is a cardiac stimulant. There is a positive inotropic and dose-dependent chronotropic response. Tachydysrhythmias, especially supraventricular tachycardia, are common due to adenosine receptor antagonism. Ventricular tachydysrhythmias can occur as well in acute overdose; however, they are rare at therapeutic concentrations. Rapid administration of aminophylline has resulted in sudden cardiac death. Hypokalemia, hypercalcemia, and hyperglycemia may contribute to arrhythmias as well. In cases of chronic toxicity, dysrhythmias occur at lower serum concentrations (40–80 mg ml-1) compared to acute overdose. Theophylline will stimulate the CNS respiratory center causing increased respiratory rate and can lead to respiratory alkalosis. Theophylline will cause CNS stimulation and vasoconstriction, similar to caffeine, and may lead to headache, anxiety, agitation, insomnia, tremor, irritability, hallucinations, and seizures. Methylxanthines exhibit weak diuretic effects by increasing cardiac output and renal vasodilation. Theophylline has a narrow therapeutic index, with 12–25% of overdose patients developing serious or life-threatening symptoms including arrhythmias and seizure. Toxicity can develop at lower serum concentrations for those treated chronically or older patients. Age greater than 60 years and chronic use are risk factors for increased morbidity and mortality.

8.77(at 25℃)

5.5×108mol/(m3Pa) at 25℃, HSDB (2015)

Slightly soluble in water.

Theophylline neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen may be generated in combination with strong reducing agents, such as hydrides.

2-8°C