Atenolol
Atenolol. Cardioselective β₁ antagonist; negligible β₂ at therapeutic doses. Hydrophilic → low CNS penetration (less nightmares / depression… Oral half-life 6.1 h.
Cardioselective β₁ antagonist; negligible β₂ at therapeutic doses. Hydrophilic → low CNS penetration (less nightmares / depression than propranolol). Renal elimination — accumulates in CKD.
PK: THE CONTROL OF ITS GROUP, AND IT MOSTLY HOLDS. F 0.5 verifies ("The bioavailability of approximately 50% is due to reduced absorption") and is independently confirmed at 50% by a second intravenous-and-oral study. The half-life of 6 h was the UPPER ENDPOINT of a stated "5-6 h" and is replaced by a genuine mean, "The mean (+/- SD) terminal elimination half-life is 6.06 +/- 2.02 hr". ka 0.7 IS THE CLEANEST BACK-DERIVATION OF THE BATCH: it reproduces a 3.08 h peak, the midpoint of its abstract "Peak blood levels are observed at 2-4 h", and an independent study reports the Tmax as "(3.0 hr)". A Tmax read backwards. The only measured absorption quantity anywhere is "the time for half of the bioavailable dose to be absorbed (2.0 hr)", implying 0.35 — half the stored value — but that came from a THREE-COMPARTMENT fit where the relation does not hold, so no replacement is stored. V 67 L is unsupported by any abstract; the only candidate is a CENTRAL-COMPARTMENT volume of 0.173 L/kg, a different parameter, so the stored value is retained rather than replaced by a wrong quantity. EFFECT COMPARTMENT: A RAT VALUE THAT READ AS HUMAN. The rate is verbatim from a WKY-rat heart-rate model — its own title says "in rats" — and the species field was unset, so it counted among the records claiming a fitted human keo. The value itself is class-typical for a β-blocker heart-rate endpoint and is kept; only the label was missing.
Pharmacokinetics
- Oral — t½ 6.1 h · F 50% · Vd 67 L
Sources: PMID:1982759, PMID:15060759, PMID:428185, PMID:6749509