Reversibly inhibits COX 1 and 2 enzymes
causing decreased production of prostaglandin precursors

mod affinity for μ receptors, weak κ, δ
-in spinal desc inh pathways by inh of neuronal reuptake of norad&serotonin
-presynaptic stim of seritonin release

As an anti-inflammatory, anti-pyretic and mild analgesic

CNS:
- Analgesia
- Hallucinations
- Confusion
- Delirium
- Agitation
- Seizures
- Coma (Serotonin syndrome)

Respiratory depression and
constipation

Rapidly absorbed
85% bioavailability

Bioavailability- 75% PO

pKa 4.5, weak acid therefore mostly unionised, abs via gut and SB

Crosses placenta
Lipid soluble-crosses BBB

99% protein bound (may displace highly protein bound drugs such as warfarin altering PD properties)

Low plasma protein binding, approximately 20%.

Very small Vd 0.1L/kg

2.9-4.37 L/kg.

hepatic via oxidation

Extensively hepatic via demethylation ,
glucuronidation, and sulfation; active metabolite by CYP2D6 (M1; O-desmethyl tramadol)

excreted as metabolites in urine 1% unchanged

Urine 90% (30% unchanged), 10% faeces.

half life 2-3 hours

T1/2: ~6-8 hrs;
Act metab:7-9hrs;
old, hepatic/renal imp.

Worsen renal function by inhibiting PGE2 and causing vasoconstriction.
 risk of thromboembolic events.
Increased risk of GI bleeding and ulceration, GORD.
Impair platelet function
May reduce the beneficial eff¬ects of aspirin

Dysphoria,Euphoria. Miosis (excitation of Edinger-Westphal nucleus)
N/V -CTZ stim. Serotonin syndrome with SSRI /SNRI/MAO/TCA
Less resp dep than morphine
analgesic effect in CYP2D6 deficiency

Non-Opiate Analgesic

Opiate Analgesic

Analgesia
Antipyretic
Antiinflammatory

Analgesia

non selective cycloxygenase inhibitor

Is a synthetic opioid – cyclohexanol derivative
Racemic mix.

Level 3

Level 2

mod affinity for μ receptors, weak κ, δ

onset 30 mins, duration 6 hours

onset / duration ~1 hour / 9 hours (immediate release)

200mg tablets, some formulations in combination with codiene

immediate release, 12 hour release and 24 hour release
tablets, IV

Tablets for PO/PR

Route- PO/IV
Dose- 50-100mg QID for all routes
(Relative pot 0.2)