Propofol
2,6-di(propan-2-yl)phenol
Overview
Propofol belongs to Anesthetics.
Effects
- Rapid onset of sedation, then hypnosis and, at anaesthetic doses, unconsciousness within about a minute of intravenous injection. Recovery is fast and often described as clear-headed, sometimes with mild euphoria or a sense of well-being on emergence.
- It produces no analgesia, pain is not blunted, and the injection itself is often painful. Amnesia for the period of sedation is typical.
- Dose-dependent respiratory depression (progressing to apnoea) and a fall in blood pressure accompany hypnotic doses. There is no safe recreational dose and no reversal agent.
Dosing & duration
Intravenous only (as a lipid emulsion). Propofol is not active orally (extensive first-pass metabolism) and is never taken by mouth clinically.. Propofol is a hospital anaesthetic, not a recreational drug, and the figures below are clinical reference doses for trained anaesthesia providers, not a guide to self-administration. It has an extremely narrow safety margin: hypnotic doses routinely cause apnoea and a fall in blood pressure, and it must be given only with full airway and resuscitation support. Non-medical use, including by healthcare workers with access, is frequently fatal, because the dose that produces anaesthesia and the dose that produces fatal respiratory arrest are very close and there is no reversal agent.
Dose ranges
1.5–2.5 mg/kg IV
4–12 mg/kg/h IV
0.5–1 mg/kg IV, then titrated
Duration
≈30–60 seconds (IV)
≈5–10 minutes after a single bolus (terminated by redistribution)
Rapid, usually clear recovery. Short-lived residual sedation and impairment
Chemical & Physical Properties
| Formula | C12H18O |
| Molar mass | 178.27 g/mol |
| State | Liquid (oily, mp 18 °C) |
| Melting point | 18 °C |
| Boiling point | 256 °C |
| Density | 0.955 g/cm³ at 20 °C |
| Vapor pressure | Not reported |
| pKa | 11.1 (20 °C) |
| LogP | 3.79 |
| Solubility | Practically insoluble in water (~124–158 mg/L). Soluble in alcohol and toluene, Formulated for use as a 1% oil-in-water lipid emulsion |
| Refractive index | 1.5134 at 20 °C, 1.5111 at 25 °C |
Identifiers & Synonyms
| CAS | 2078-54-8 |
| CAS (enantiomer) | |
| PubChem CID | 4943 |
| InChIKey | OLBCVFGFOZPWHH-UHFFFAOYSA-N |
| InChI | InChI=1S/C12H18O/c1-8(2)10-6-5-7-11(9(3)4)12(10)13/h5-9,13H,1-4H3 |
| SMILES | CC(C)C1=C(C(=CC=C1)C(C)C)O |
Synonyms
- Diprivan
- 2,6-diisopropylphenol
Pharmacodynamics & Biochemistry
Propofol (2,6-diisopropylphenol) is a short-acting intravenous general anaesthetic and sedative-hypnotic. It has no analgesic activity. Its actions are sedation, hypnosis and amnesia. Its principal molecular action is positive allosteric modulation of GABA-A receptors: at clinical concentrations it potentiates GABA-evoked chloride currents, and at higher concentrations it directly activates the receptor. This enhancement of inhibitory GABAergic transmission produces sedation, hypnosis and, at anaesthetic doses, unconsciousness. The hypnotic and immobilising actions depend particularly on GABA-A receptors containing the β3 subunit: a point mutation (N265M) in β3 strongly attenuates propofol's effects in vivo, identifying a transmembrane β-subunit site as the key locus of action. Propofol has weaker secondary actions at other channels. It blocks HCN1 channels, inhibits mechanosensitive TRPV4 and Piezo1/Piezo2 channels and some voltage-gated sodium channels, and modulates glycine receptors, but these occur mostly at higher, supra-clinical concentrations and are minor relative to its GABA-A action (which is why no binding table is shown: the databased quantitative values are only for these off-targets).
Biological targets
- GABA-A
Binding & functional measurements
Pharmacokinetics
| Bioavailability | Intravenous (100%), orally inactive (extensive first-pass metabolism) |
| Tmax | Effect within ≈30–60 s of an IV bolus |
| Half-life | Rapid distribution (t½α ≈2–4 min), clinically short-acting by redistribution, with a long terminal half-life from deep (fat) compartments |
| Vd | Not reported |
| Protein binding | ≈97–99% (highly protein-bound and highly lipophilic) |
| Metabolism | Rapid hepatic and extrahepatic glucuronidation/hydroxylation (high clearance) |
| Excretion | Renal (inactive metabolites) |
Toxicology & Safety
Not reported
Propofol is one of the most widely used intravenous anaesthetics, but it is dangerous outside a controlled clinical setting. Hypnotic doses reliably cause respiratory depression and apnoea together with a drop in blood pressure, and there is no reversal agent: the margin between sedation and fatal respiratory arrest is small. Injection is often painful. Prolonged high-dose infusion can cause propofol infusion syndrome (PRIS): metabolic acidosis, rhabdomyolysis, hyperkalaemia and cardiac failure, which can be fatal and is a particular risk in children and the critically ill. Propofol also has genuine abuse potential: misuse for its rapid sedative, sleep-inducing and mildly euphoric effects, especially among anaesthesia and other healthcare workers with access, has caused numerous deaths, because self-administration without airway support readily proceeds to fatal apnoea.[3][6]
Legal Status
US: Prescription only. UK: Prescription only (POM). DE: Prescription only (Rx)
Interactions & Contraindications
Drug interactions
Contraindications
No interactions or contraindications listed.
Usage & Context
- A first-line intravenous agent for induction and maintenance of general anaesthesia, for procedural (conscious) sedation, and for sedation of ventilated patients in intensive care. Valued for its rapid onset and rapid, clear recovery.
- Despite hospital-only availability it is misused for its rapid sedative and sleep-inducing effects, most notoriously among healthcare workers: a pattern associated with a high death rate because of the ease of fatal respiratory depression.
Sources & Evidence
- PubChem: Propofol (CID 4943) — identifiers & experimental properties
- IUPHAR/BPS Guide to PHARMACOLOGY: propofol (ligand 5464) — GABA-A comments and secondary ion-channel actions (HCN1, TRPV4, Piezo1/2) CC BY-SA 4.0
- Sahinovic MM, Struys MMRF, Absalom AR (2018). Clinical Pharmacokinetics and Pharmacodynamics of Propofol. Clin Pharmacokinet 57:1539-1558.
PMID 30019172 · doi:10.1007/s40262-018-0672-3
- Trapani G, Altomare C, Liso G, et al. (2000). Propofol in anesthesia. Mechanism of action, structure-activity relationships, and drug delivery. Curr Med Chem 7:249-71.
PMID 10637364 · doi:10.2174/0929867003375335
- Jurd R, Arras M, Lambert S, et al. (2003). General anesthetic actions in vivo strongly attenuated by a point mutation in the GABA(A) receptor beta3 subunit. FASEB J 17:250-2.
PMID 12475885 · doi:10.1096/fj.02-0611fje
- Wikipedia: Propofol (clinical use, adverse effects, misuse & legal status) CC BY-SA 4.0