Theophylline and other methylxanthines are often used for their performance-enhancing effects in sports, as these drugs increase alertness, bronchodilation, and increase the rate and force of heart contraction.[10] There is conflicting information about the value of theophylline and other methylxanthines as prophylaxis against exercise-induced asthma.[11]
Adverse effects
The use of theophylline is complicated by its interaction with various drugs and by the fact that it has a narrow therapeutic window (<20 mcg/mL).[2] Its use must be monitored by direct measurement of serum theophylline levels to avoid toxicity. It can also cause nausea, diarrhea, increase in heart rate, abnormal heart rhythms, and CNS excitation (headaches, insomnia, irritability, dizziness and lightheadedness).[2][12]Seizures can also occur in severe cases of toxicity, and are considered to be a neurological emergency.[2]
Its toxicity is increased by erythromycin, cimetidine, and fluoroquinolones, such as ciprofloxacin. Some lipid-based formulations of theophylline can result in toxic theophylline levels when taken with fatty meals, an effect called dose dumping, but this does not occur with most formulations of theophylline.[13] Theophylline toxicity can be treated with beta blockers. In addition to seizures, tachyarrhythmias are a major concern.[14] Theophylline should not be used in combination with the SSRIfluvoxamine.[15][16]
Spectroscopy
UV-visible
Theophylline is soluble in 0.1N NaOH and absorbs maximally at 277 nm with an extinction coefficient of 10,200 (cm−1 M−1).[17]
Proton NMR
The characteristic signals, distinguishing theophylline from related methylxanthines, are approximately 3.23δ and 3.41δ, corresponding to the unique methylation possessed by theophylline. The remaining proton signal, at 8.01δ, corresponds to the proton on the imidazole ring, not transferred between the nitrogen. The transferred proton between the nitrogen is a variable proton and only exhibits a signal under certain conditions.[18]
13C-NMR
The unique methylation of theophylline corresponds to the following signals: 27.7δ and 29.9δ. The remaining signals correspond to carbons characteristic of the xanthine backbone.[19]
Natural occurrences
Theophylline is naturally found in cocoa beans. Amounts as high as 3.7 mg/g have been reported in Criollo cocoa beans.[20]
Trace amounts of theophylline are also found in brewed tea, although brewed tea provides only about 1 mg/L,[21] which is significantly less than a therapeutic dose.
nonselective adenosine receptor antagonist, antagonizing A1, A2, and A3 receptors almost equally, which explains many of its cardiac effects.[2][27] Theophylline activates histone deacetylases.[2]
Theophylline is distributed in the extracellular fluid, in the placenta, in the mother's milk and in the central nervous system. The volume of distribution is 0.5 L/kg. The protein binding is 40%.[medical citation needed]
Metabolism
Theophylline is metabolized extensively in the liver.[2] It undergoes N-demethylation via cytochrome P450 1A2. It is metabolized by parallel first order and Michaelis-Menten pathways. Metabolism may become saturated (non-linear), even within the therapeutic range. Small dose increases may result in disproportionately large increases in serum concentration. Methylation to caffeine is also important in the infant population. Smokers and people with hepatic (liver) impairment metabolize it differently.[2] Cigarette and marijuana smoking induces metabolism of theophylline, increasing the drug's metabolic clearance.[29][30]
Excretion
Theophylline is excreted unchanged in the urine (up to 10%). Clearance of the drug is increased in children (age 1 to 12), teenagers (12 to 16), adult smokers, elderly smokers, as well as in cystic fibrosis, and hyperthyroidism. Clearance of the drug is decreased in these conditions: elderly, acute congestive heart failure, cirrhosis, hypothyroidism and febrile viral illnesses.[2]
The elimination half-life varies: 30 hours for premature neonates, 24 hours for neonates, 3.5 hours for children ages 1 to 9, 8 hours for adult non-smokers, 5 hours for adult smokers, 24 hours for those with hepatic impairment, 12 hours for those with congestive heart failure NYHA class I-II, 24 hours for those with congestive heart failure NYHA class III-IV, 12 hours for the elderly.[medical citation needed]
History
Theophylline was first extracted from tea leaves and chemically identified around 1888 by the German biologist Albrecht Kossel.[31][32] Seven years later, a chemical synthesis starting with 1,3-dimethyluric acid was described by Emil Fischer and Lorenz Ach.[33] The Traube purine synthesis, an alternative method to synthesize theophylline, was introduced in 1900 by another German scientist, Wilhelm Traube.[34] Theophylline's first clinical use came in 1902 as a diuretic.[35] It took an additional 20 years until it was first reported as an asthma treatment.[36] The drug was prescribed in a syrup up to the 1970s as Theostat 20 and Theostat 80, and by the early 1980s in a tablet form called Quibron.
^Hung KC, Ho CN, Chen IW, Hung IY, Lin MC, Lin CM, et al. (August 2021). "The impact of aminophylline on incidence and severity of post-dural puncture headache: A meta-analysis of randomised controlled trials". Anaesthesia, Critical Care & Pain Medicine. 40 (4): 100920. doi:10.1016/j.accpm.2021.100920. PMID34186265. S2CID235686558.
^"Theophylline". MedlinePlus Drug Information. U.S. National Library of Medicine. Archived from the original on July 5, 2016.
^Hendeles L, Weinberger M, Milavetz G, Hill M, Vaughan L (June 1985). "Food-induced "dose-dumping" from a once-a-day theophylline product as a cause of theophylline toxicity". Chest. 87 (6): 758–765. doi:10.1378/chest.87.6.758. PMID3996063. S2CID1133968.
^Seneff M, Scott J, Friedman B, Smith M (June 1990). "Acute theophylline toxicity and the use of esmolol to reverse cardiovascular instability". Annals of Emergency Medicine. 19 (6): 671–673. doi:10.1016/s0196-0644(05)82474-6. PMID1971502.
^DeVane CL, Markowitz JS, Hardesty SJ, Mundy S, Gill HS (September 1997). "Fluvoxamine-induced theophylline toxicity". The American Journal of Psychiatry. 154 (9): 1317–1318. doi:10.1176/ajp.154.9.1317b. PMID9286199.
^Schack JA, Waxler SH (November 1949). "An ultraviolet spectrophotometric method for the determination of theophylline and theobromine in blood and tissues". The Journal of Pharmacology and Experimental Therapeutics. 97 (3): 283–291. PMID15392550.
^Shelke RU, Degani MS, Raju A, Ray MK, Rajan MG (August 2016). "Fragment Discovery for the Design of Nitrogen Heterocycles as Mycobacterium tuberculosis Dihydrofolate Reductase Inhibitors". Archiv der Pharmazie. 349 (8): 602–613. doi:10.1002/ardp.201600066. PMID27320965. S2CID40014874.
^Pfleiderer W (February 2008). "Pteridines. Part CXIX. A New Pteridine–Purine Transformation". Helvetica Chimica Acta. 91 (2): 338–353. doi:10.1002/hlca.200890039.
^Belliardo F, Martelli A, Valle MG (May 1985). "HPLC determination of caffeine and theophylline in Paullinia cupana Kunth (guarana) and Cola spp. samples". Zeitschrift für Lebensmittel-Untersuchung und -Forschung. 180 (5): 398–401. doi:10.1007/BF01027774. PMID4013524. S2CID40205323.
^Marques LJ, Zheng L, Poulakis N, Guzman J, Costabel U (February 1999). "Pentoxifylline inhibits TNF-alpha production from human alveolar macrophages". American Journal of Respiratory and Critical Care Medicine. 159 (2): 508–511. doi:10.1164/ajrccm.159.2.9804085. PMID9927365.
^Daly JW, Jacobson KA, Ukena D (1987). "Adenosine receptors: development of selective agonists and antagonists". Progress in Clinical and Biological Research. 230 (1): 41–63. PMID3588607.
^Griffin JP (2009). The Textbook of Pharmaceutical Medicine (6th ed.). Chichester: Wiley-Blackwell. ISBN978-1-4051-8035-1.
^Jenne JW, Nagasawa HT, Thompson RD (March 1976). "Relationship of urinary metabolites of theophylline to serum theophylline levels". Clinical Pharmacology and Therapeutics. 19 (3): 375–381. doi:10.1002/cpt1976193375. PMID1261172. S2CID33943915.
^Jusko WJ, Schentag JJ, Clark JH, Gardner M, Yurchak AM (October 1978). "Enhanced biotransformation of theophylline in marihuana and tobacco smokers". Clinical Pharmacology and Therapeutics. 24 (4): 405–410. doi:10.1002/cpt1978244406. PMID688731. S2CID44613672.
^Kossel A (1889). "Über das Theophyllin, einen neuen Bestandtheil des Thees" [On theophylline, a new component of tea]. Hoppe-Seyler's Zeitschrift für Physiologische Chemie [Hoppe-Seyler's Journal of Physiological Chemistry] (in German). 13: 298–308.
^Fischer E, Ach L (1895). "Synthese des Caffeins" [Synthesis of caffeine]. Berichte der Deutschen Chemischen Gesellschaft [Reports of the German Chemical Society] (in German). 28 (3): 3139. doi:10.1002/cber.189502803156.
^Minkowski O (1902). "Über Theocin (Theophyllin) als Diureticum" [About theocine (theophylline) as a diuretic]. Therapie der Gegenwart [Therapy of the Present] (in German). 43: 490–493.
^Schultze-Werninghaus G, Meier-Sydow J (March 1982). "The clinical and pharmacological history of theophylline: first report on the bronchospasmolytic action in man by S. R. Hirsch in Frankfurt (Main) 1922". Clinical Allergy. 12 (2): 211–215. doi:10.1111/j.1365-2222.1982.tb01641.x. PMID7042115. S2CID38178598.
External links
Media related to Theophylline at Wikimedia Commons