Caffeine

Caffeine

Clinical data
Pronunciation	/kæˈfiːn, ˈkæfiːn/
Synonyms	Guaranine Methyltheobromine 1,3,7-Trimethylxanthine 7-methyltheophylline[6] Theine
AHFS/Drugs.com	Monograph
Pregnancy category	AU: A
Dependence liability	Physical: low–moderate[1][2][3][4] Psychological: low[5]
Addiction liability	Low[4] / none[1][2][3]
Routes of administration	By mouth, insufflation, enema, rectal, intravenous
Drug class	Stimulant
ATC code	N06BC01 (WHO) D11AX26 (WHO), V04CG30 (WHO)
Legal status
Legal status	CA: Unscheduled UK: General sales list (GSL, OTC) US: Unscheduled
Pharmacokinetic data
Bioavailability	99%[8]
Protein binding	25–36%[7]
Metabolism	Primary: CYP1A2[7] Minor: CYP2E1,[7] CYP3A4,[7] CYP2C8,[7] CYP2C9[7]
Metabolites	Paraxanthine (84%) Theobromine (12%) Theophylline (4%)
Onset of action	~1 hour[8]
Elimination half-life	Adults: 3–7 hours[7] Infants (full term): 8 hours[7] Infants (premature): 100 hours[7]
Duration of action	3–4 hours[8]
Excretion	Urine (100%)
Identifiers
IUPAC name 1,3,7-Trimethylpurine-2,6-dione
CAS Number	58-08-2 Y
PubChem CID	2519
IUPHAR/BPS	407
DrugBank	DB00201 Y
ChemSpider	2424 Y
UNII	3G6A5W338E
KEGG	D00528 Y
ChEBI	CHEBI:27732 Y
ChEMBL	ChEMBL113 Y
PDB ligand	CFF (PDBe, RCSB PDB)
ECHA InfoCard	100.000.329
Chemical and physical data
Formula	C8H10N4O2
Molar mass	194.19 g·mol−1
3D model (JSmol)	Interactive image
Density	1.23 g/cm3
Melting point	235 to 238 °C (455 to 460 °F) (anhydrous)[9][10]
SMILES CN1C=NC2=C1C(=O)N(C(=O)N2C)C
InChI InChI=1S/C8H10N4O2/c1-10-4-9-6-5(10)7(13)12(3)8(14)11(6)2/h4H,1-3H3 Key:RYYVLZVUVIJVGH-UHFFFAOYSA-N Y

Caffeine is a central nervous system (CNS) stimulant. It is in the methylxanthine class. It is found in many plants, and is used in drinks like coffee, some teas, some soft drinks, and energy drinks. It can be harmful for both humans and animals if a large amount is consumed. If a person ate 10-13 grams of caffeine quickly, between 80 and 100 cups of coffee, they would overdose and may die.^[11] It is the world's most popular psychoactive drug, and is legal in nearly all of the world.^[12]

1. ↑ ^{1.0 1.1} Malenka RC, Nestler EJ, Hyman SE (2009). "Chapter 15: Reinforcement and Addictive Disorders". In Sydor A, Brown RY (eds.). Molecular Neuropharmacology: A Foundation for Clinical Neuroscience (2nd ed.). New York: McGraw-Hill Medical. p. 375. ISBN 978-0-07-148127-4. Long-term caffeine use can lead to mild physical dependence. A withdrawal syndrome characterized by drowsiness, irritability, and headache typically lasts no longer than a day. True compulsive use of caffeine has not been documented.
2. ↑ ^{2.0 2.1} Karch SB (2009). Karch's pathology of drug abuse (4th ed.). Boca Raton: CRC Press. pp. 229–230. ISBN 978-0-8493-7881-2.
3. ↑ ^{3.0 3.1} American Psychiatric Association (2013). "Substance-Related and Addictive Disorders" (PDF). American Psychiatric Publishing. pp. 1–2. Archived from the original (PDF) on 15 August 2015. Retrieved 10 July 2015. Substance use disorder in DSM-5 combines the DSM-IV categories of substance abuse and substance dependence into a single disorder measured on a continuum from mild to severe. ... Additionally, the diagnosis of dependence caused much confusion. Most people link dependence with "addiction" when in fact dependence can be a normal body response to a substance. ... DSM-5 will not include caffeine use disorder, although research shows that as little as two to three cups of coffee can trigger a withdrawal effect marked by tiredness or sleepiness. There is sufficient evidence to support this as a condition, however it is not yet clear to what extent it is a clinically significant disorder.
4. ↑ ^{4.0 4.1} Introduction to Pharmacology (third ed.). Abingdon: CRC Press. 2007. pp. 222–223. ISBN 978-1-4200-4742-4.
5. ↑ Juliano LM, Griffiths RR (October 2004). "A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features". Psychopharmacology. 176 (1): 1–29. doi:10.1007/s00213-004-2000-x. PMID 15448977. S2CID 5572188.
6. ↑ "Caffeine". ChemSpider. Retrieved 16 November 2021.
7. ↑ ^{7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8} "Caffeine". DrugBank. University of Alberta. 16 September 2013. Retrieved 8 August 2014.
8. ↑ ^{8.0 8.1 8.2} Poleszak E, Szopa A, Wyska E, Kukuła-Koch W, Serefko A, Wośko S, Bogatko K, Wróbel A, Wlaź P (February 2016). "Caffeine augments the antidepressant-like activity of mianserin and agomelatine in forced swim and tail suspension tests in mice". Pharmacological Reports. 68 (1): 56–61. doi:10.1016/j.pharep.2015.06.138. PMID 26721352. S2CID 19471083.
9. ↑ "Caffeine". Pubchem Compound. NCBI. Retrieved 16 October 2014.
   Boiling Point
   178 °C (sublimes)
   Melting Point
   238 DEG C (ANHYD)
10. ↑ "Caffeine". ChemSpider. Royal Society of Chemistry. Retrieved 16 October 2014. Experimental Melting Point:
    234–236 °C Alfa Aesar
    237 °C Oxford University Chemical Safety Data
    238 °C LKT Labs [C0221]
    237 °C Jean-Claude Bradley Open Melting Point Dataset 14937
    238 °C Jean-Claude Bradley Open Melting Point Dataset 17008, 17229, 22105, 27892, 27893, 27894, 27895
    235.25 °C Jean-Claude Bradley Open Melting Point Dataset 27892, 27893, 27894, 27895
    236 °C Jean-Claude Bradley Open Melting Point Dataset 27892, 27893, 27894, 27895
    235 °C Jean-Claude Bradley Open Melting Point Dataset 6603
    234–236 °C Alfa Aesar A10431, 39214
    Experimental Boiling Point:
    178 °C (Sublimes) Alfa Aesar
    178 °C (Sublimes) Alfa Aesar 39214
11. ↑ "Can caffeine kill you?". Livescience.com. 25 September 2012. Retrieved 19 February 2016.
12. ↑ Burchfield G (1997). Meredith H (ed.). "What's your poison: caffeine". Australian Broadcasting Corporation. Archived from the original on 26 July 2009. Retrieved 15 January 2014.