Pharmacokinetics
Pharmacokinetic properties (see table 3) are important when new drugs are developed.
Patients seek rapid onset of action to relief the headache. Relatively short tmax, good bioavailability and lipophilicity are pharmacokinetic properties that have been associated with rapid onset of action. It has been speculated that good ability to cross the blood brain barrier and relatively long terminal elimination half-life may result in a lower incidence of headache recurrence. Sumatriptan and rizatriptan undergo first pass hepatic metabolism and result in lower bioavailability.
| Generic | Bioavailability (%) | Lipophilicity | Protein binding (%) |
t1/2 (h) | tmax (h) | ClR (mL min-1) |
Log DpH7.4 | VD |
|---|---|---|---|---|---|---|---|---|
| Sumatriptan | 14 | Low | 10–21 | 2–2.5 | 2–2,5 | 260 | -1.5 | 2.4–3.3 L/kg |
| Zolmitriptan | 40 | Moderate | 25 | 3 | 2 | 193 | -1.0 | 7.0 L/kg |
| Naratriptan | 63(M) / 74(F) | High | 28–31 | 5–6 | 2–3 | 220 | -0.2 | 2.4 L/kg |
| Rizatriptan | 47 | Moderate | 14 | 2–2.5 | 1.3 | 414 | -0.7 | 140(M) / 110(F) L |
| Almotriptan | 69 | – | 35 | 3.5 | 1.4–3.8 | – | -2.1 | 180–200 L |
| Eletriptan | 50 | High | 85 | 4–5 | 1–2 | 597 | 0.5 | 138 L |
| Frovatriptan | 24(M) / 30(F) | Low | 20–30 | 2–5 | 2–4 | 216(M) / 132(F) | -1.0 | 4.2(M) / 3.0(F) L/kg |
Read more about this topic: Discovery And Development Of Triptans, Triptan Drugs