Effects of adrenaline during treatment with propranolol and metoprolol

Potential drug-drug interactions in a medical intensive care unit of a university hospital

BACKGROUND/AIM

Drug-drug interactions (DDIs) can impact patient safety. Occurrence of clinically important DDIs is higher for intensive care unit (ICU) patients. This observational study aimed to evaluate the potential DDIs in medical ICU patients of a university hospital.

MATERIALS AND METHODS

The Medical Pharmacology Department organized consultation reports for ICU patients in order to detect the DDIs. To focus on clinically important DDIs, interactions in the C, D, or X risk rating categories of the Lexi-Interact online database were analyzed. Frequency and clinical risk rating categories of DDIs were detected. Relationship between number of prescriptions and DDIs were assessed. The most frequent drug/drug groups were identified.

RESULTS

Of 101 ICU patients, 45.5% were found to have DDIs. We detected 125 C (72.2%), 37 D (21.4%), and 11 X (6.4%) risk category interactions. A statistically significant increase in the number of DDIs was shown with the number of prescriptions (P = 0.002). The most frequent DDIs were between agents acting on the cardiovascular system and corticosteroids (12.8%).

CONCLUSION

Results of this study show that pharmacological consultation plays a critical role in the recognition of DDIs for improvement of medication management and effective therapeutic endpoints without any adverse or toxic reactions.

Vasospastic phenomena in patients treated with beta-adrenoceptor blocking agents

Twenty-one patients developed Raynaud's phenomenon during treatment with beta-adrenoceptor blocking agents. The vasospastic symptoms were obviously related to the treatment, but their pathogenesis is still controversial. A decrease in cardiac output might explain the phenomenon. According to our very preliminary data an alpha-adrenergic dominance caused by a direct effect on the peripheral circulation seems more probable. Vasospastic symptoms may arise after treatment with both cardioselective and non-selective beta blocking agents. Cautious prescription of beta blocking drugs to patients with preexisting peripheral vascular disease is recommended.

Anesthetic formulation of tumescent solutions

There is no standard or official recipe for the tumescent anesthetic solutions. The actual concentrations of lidocaine and epinephrine should depend on the areas to be treated and clinical situation. This article discusses the safe usage of tumescent solutions and the proper procedures and precautions to take when mixing these solutions.

Noninvasive measurement of femoral blood flow and portal pressure response to propranolol in patients with cirrhosis

This study investigated the correlation between changes in hepatic and systemic hemodynamics and femoral blood flow (FBF), measured by dual-beam pulsed wave Doppler, in 58 portal hypertensive patients receiving propranolol (0.15 mg/Kg intravenously; n = 44) or placebo (n = 14) under double-blind conditions. Placebo administration had no effects. Propranolol caused significant reductions (P < .0001) in hepatic venous pressure gradient (HVPG; from 19.1 +/- 4.1 to 16.2 +/- 4.2 mm Hg), azygos blood flow (from 563 +/- 204 to 387 +/- 176 mL/min), cardiac index (CI; from 4.4 +/- 1.0 to 3.3 +/- 0.8 L/m2/min), and FBF (from 237 +/- 79 to 176 +/- 58 mL/m2/min). In 17 patients HVPG decreased below 12 mm Hg and/or more than 20% of the baseline value (good response; mean change, -26 +/- 8%); in the remaining 27 patients (poor response) the mean change in HVPG was less: -9 +/- 6%. Patients with a good response had bled less often from varices, had significantly higher FBF (272 +/- 73 vs. 215 +/- 76 mL/m2/min) and lower baseline HVPG (16.8 +/- 3.9 vs. 20.6 +/- 3.6 mm Hg) than those with poor response in HVPG. The good response was also associated with greater decreases in FBF (-33 +/- 12 vs. -19 +/- 13% in poor responders), CI (-30 +/- 9 vs. -19 +/- 12%), and heart rate (-19 +/- 5 vs. -16 +/- 6%). A decrease in FBF of > 20% predicted a good response in 16 of 28 patients (positive predictive value, 57%).(ABSTRACT TRUNCATED AT 250 WORDS)

Haemodynamic effects of metoprolol and pindolol: a comparison in hypertensive patients

1 In a double-blind study, 36 patients with essential hypertension were randomly allocated to treatment with either metoprolol, 100--300 mg/day, or pindolol, 5--15 mg/day for 6 months. Haemodynamic investigations were made on three separate occasions. Blood flow in the calves and in the forearm was determined by venous occlusion plethysmography after 6 weeks of placebo, after 6 weeks and again after 6 months of active therapy. 2 Both drugs reduced blood pressure significantly, by 17.1/11.8 mm Hg with metoprolol and 21.9/10.9 mm Hg with pindolol after 6 weeks (P less than 0.005). No further changes were seen after 6 months. 3 Heart rate after 6 weeks was significantly reduced by metoprolol (10.7 +/- 2.4 beats/min, P less than 0.001) but not by pindolol (4.4 +/- 2.3 beats/min, NS). After 6 months a significant reduction was seen also in the pindolol group (5.2 +/- 2.1 beats/min, P less than 0.05). 4 The vascular resistance in the calves at rest was reduced by pindolol (P less than 0.05), whereas resistance tended to increase with metoprolol. 5 Resting vascular resistance in the forearm after 6 months was significantly reduced in the metoprolol group (P less than 0.001) as well as in the pindolol group (P less than 0.02). The increase in forearm vascular resistance seen during leg exercise was not influenced by either drug. 6 Vascular resistance at maximal vasodilatation was unchanged in the calves, but a significant reduction (-17.4 +/- 5.7%, P less than 0.01) in the forearm vascular bed was seen after 6 months of pindolol. No change was observed with metoprolol. 7 It is concluded that pindolol reduces elevated blood pressure partly through peripheral vascular mechanism. Metoprolol, on the other hand, probably acts mainly via central cardiac mechanisms.

Effect of metoprolol on blood glycerol, free fatty acids, triglycerides and glucose in relation to plasma catecholamines in hypertensive patients at rest and following submaximal work

Studies were performed in nine male patients with moderate hypertension. Treatment with metoprolol, 50--150 mg three times daily for 4--17 weeks, had no effect on the plasma level of glycerol, free fatty acids, triglycerides or glucose under basal conditions, neither in the supine nor in the upright position. Submaximal work, performed postprandially, increased plasma glycerol before medication but not during metoprolol, in spite of a marked increase in plasma noradrenaline. The work load employed caused no change in free fatty acids, triglycerides or glucose, neither before medication nor during metoprolol.

Metoprolol: a review of its pharmacological properties and therapeutic efficacy in hypertension and angina pectoris

Metoprolol is a beta1-selective adrenoceptor blocking drug. In hypertension, its duration of effect is longer than expected from its half-life and it is suitable for twice daily administration. There is some evidence that once daily administration may be possible in treating hypertension. It is similar in efficacy to other beta-adrenoceptor blocking drugs in angina pectoris and essential hypertension, when given in equiactive beta-blocking dosages. Metoprolol is well tolerated and side-effects have not proved a problem. It has some pharmacodynamic and pharmacokinetic differences from other beta-adrenoceptor blocking drugs and may prove useful in cases where these differences are shown to be clinically important.