Among other drugs in the beta-blocker class, Acebutolol will provide beta-blockade effects to a lesser extent. Due to its cardioselectivity, Acebutolol is more suitable than non-cardioselective beta-blockers, in a patient with asthma or chronic obstructive pulmonary disease (COPD) who needs treatment with a beta-blocker. This cardio-specificity will minimize the anti-hypertensive effects as seen with non-specific beta blockers such as Propanalol and Nadolol. (For these reasons, it may be a beta-blocker of choice in inclusion in Polypill strategies). In doses lower than 800 mg daily its constricting effects on the bronchial system and smooth muscle vessels are only 10% to 30% of those observed under propranolol treatment, but there is experimental evidence that the cardioselective properties diminish at doses of 800 mg/day or more. The drug has lipophilic properties and therefore crosses the blood–brain barrier. Acebutolol has no negative impact on serum lipids (cholesterol and triglycerides). No HDL decrease has been observed. In this regard, it is unlike many other beta-blockers which have this unfavourable property. The drug works in hypertensive patients with high, normal, or low renin plasma concentrations, although acebutolol may be more efficient in patients with high or normal renin plasma concentrations. In clinically relevant concentrations, a membrane-stabilizing effect does not appear to play an important role. Pharmacokinetics
Acebutolol is well absorbed from the GI tract, but undergoes substantial first-pass-metabolization, leading to a bioavailability of only 35% to 50%. Peak plasma levels of acebutolol are reached within 2 to 2.5 hours after oral dosing.
Recreational
In the 1970s, recreational drug users discovered that combining pentazocine with tripelennamine (a first-generation ethylenediamine antihistamine most commonly dispensed under the brand names Pelamine and Pyribenzamine) produced a euphoric sensation. Since tripelennamine tablets are typically blue in color and brand-name Pentazocine is known as Talwin (hence "Ts"), the pentazocine/tripelennamine combination acquired the slang name Ts and blues. After health-care professionals and drug-enforcement officials became aware of this scenario, the mu opioid receptor antagonist naloxone was added to oral preparations containing pentazocine to prevent perceived "misuse" via injection, and the reported incidence of its recreational use has declined precipitously since. Research
In an open-label, add-on, single-day, acute-dose small clinical study, pentazocine was found to rapidly and substantially reduce symptoms of mania in individuals with bipolar disorder that were in the manic phase of the condition. It was postulated that the efficacy observed was due to κ-opioid receptor activation-mediated amelioration of hyperdopaminergia in the reward pathways. Minimal sedation and no side effects including psychotomimetic effects or worsening of psychosis were observed at the dose administered. Adverse effects
Side effects are similar to those of morphine, but pentazocine, due to its action at the kappa opioid receptor is more likely to invoke psychotomimetic effects. High dose may cause high blood pressure or high heart rate. It may also increase cardiac work after myocardial infarction when given intravenously and hence this use should be avoided where possible.