A comparison of Circulatory responsiveness following the sudden withdrawal from atenolol and propranolol

The sudden withdrawal of propranolol and atenolol was studiedin five normal volunteers. Exercise testing was performed duringthe withdrawal period and physiological responsiveness comparedto control responses. A significantly heightened reactivityof the blood pressure with early exercise was found after discontinuationof both drugs. A significant acceleration of the heart raleresponse with early exercise was seen only following propranololwithdrawal. When the combined effect (heart rate x systolicblood pressure) was analyzed, a significant increase in thedouble product achieved with low levels of exercise was observedfollowing the sudden withdrawal of only propranolol administration.     

A survey on the application of oral propranolol and atenolol for the management of infantile hemangiomas in mainland China: Survey on propranolol atenolol hemangiomas

Since 2008, oral propranolol has evolved as the first-line therapy for infantile hemangiomas (IHs). Meanwhile, oral atenolol gradually shows comparative effectiveness versus oral propranolol with few side effects. Here, we conducted a mobile internal survey among a group of Chinese clinicians about how they choose the dosage, dose regimen, and dose escalation methods of propranolol and atenolol for the treatment of IH.A mobile-ready internal survey on the application of oral propranolol and oral atenolol for IH in mainland China was performed and distributed to 333 potential clinicians from different levels of healthcare institutions in mainland China. Eighty-one doctors responded to the survey. All the respondents had the experience of treating IH with oral propranolol and 32 had the experience with oral atenolol.Most of the doctors from tertiary hospitals chose 2 mg/kg/d twice daily, while most of those with the experience of propranolol from private hospitals chose 1 mg/kg/d once daily. More doctors from tertiary hospitals had the experience of atenolol than those from private hospitals.Oral atenolol has become another medication intervention option for IH in mainland China. This survey is helpful to standardize and develop a guideline of oral atenolol therapy for IH.     

Double-blind comparison of tiapamil and atenolol in patients with mild to moderate hypertension: A multicenter trial

Summary The efficacy and safety of tiapamil, a new calcium-channel blocker, was compared with the cardio-selective beta-blocker atenolol in a 16-week double-blind, multicenter trial with an initial 4-week placebo run-in period. Eighty-one outpatients with WHO stage I or II hypertension, 55 men and 26 women, entered the study. There was a total of nine drop-outs, six in the tiapamil group and three in the atenolol group. Five were due to side effects (four in the tiapamil group and one in the atenolol group). Sixty-one patients performed a graded exercise test sitting on a ergometer bicycle before and after completion of the therapy.Patients eligible for the study after the placebo period received either tiapamil 450 mg b.i.d. or atenolol 100 mg daily. Both drugs lowered systolic and diastolic blood pressure significantly. After 12 weeks of therapy, supine blood pressure in the tiapamil group fell from 167/104 mmHg to 154/91 mmHg (p<0.005), and in the atenolol group from 166/102 mmHg to 151/89 mmHg (p<0.005). A satisfactory reduction in diastolic blood pressure, defined as a reduction of more than 10 mmHg and/or values below or equal to 90 mmHg at the end of the study, was achieved in 29 of 35 patients in the tiapamil group and in 27 of 37 in the atenolol group. No changes in heart rate were observed in the tiapamil group, whereas there was a significant fall in heart rate in the atenolol group. The maximal exercise workload tolerated increased equally in both groups, from 135 to 147 watts. No changes in laboratory parameters were observed.Tiapamil seems to be an effective and safe drug in the treatment of mild to moderate hypertension and in this respect is comparable to atenolol.     

Acute drug overdose: one hospital's experience

A retrospective review of all patients admitted to an urban teaching hospital emergency department with the complaint of overdose, poisoning, or ingestion during a 10-month period was conducted. Analysis of these 82 episodes involving 69 individuals revealed: 1) a preponderance of women in the 20- to 40-year old range; 2) poly-drug character of the ingestion, with alcohol the most common secondary drug; 3) increased utilization of antidepressants and minor tranquilizers and decreased use of barbiturates; 4) non-concordance between drug history of ingested drug and toxicological findings. All patients survived and there was no apparent residual morbidity. Except for one patient requiring hemodialysis and peritoneal dialysis, all patients were treated with aggressive supportive care.     

Isoniazid overdose treated with high-dose pyridoxine

Large doses of pyridoxine recently have been shown to prevent the seizures and acidosis caused by ingestion of more than two to three grams of isoniazid. We present three cases of massive isoniazid ingestion, producing seizures and acidosis, that were treated successfully by administration of one gram of pyridoxine intravenously for each gram of isoniazid ingested.     

Seizures due to maprotiline overdose

Maprotiline, a new tetracyclic antidepressant, has a pattern of toxicity that is different from that of tricyclics. Maprotiline overdosage appears more likely to cause seizures but less likely to cause the peripheral autonomic and cardiac manifestations seen with tricyclics. Two cases of maprotiline overdose resulting in seizures without significant anticholinergic or cardiotoxic effects are presented. Both patients were treated acutely with gastric emptying and were observed to have no further seizures during subsequent drug-free hospital and outpatient follow up. Physostigmine salicylate has been used as an antidote for the anticholinergic syndrome of tricyclic overdose, but probably offers less in maprotiline overdose. Careful observation for seizures appears to be warranted.     

Comparative effects of celiprolol,propranolol, oxprenolol,and atenolol on respiratory function in hypertensive patients with chronic obstructive lung disease

Summary The aim of the study was to compare the pulmonary effects of four beta-blockers with different ancillary properties: propranolol (non-beta₁ selective without ISA), oxprenolol (non-beta₁ selective with ISA), atenolol (beta₁ selective), and celipropol (beta₁ selective with mild beta₂-agonist and alpha₂-antagonist activity) in hypertensive patients with chronic obstructive lung disease. Ten asthmatic patients, all males, aged 50–66 years were studied. Entry criteria were a) DBP95 mmHg and 115 mmHg; b) FEV₁<70% of the theoretical values; c) FEV₁ increase of at least 20% after salbutamol inhalation (200 g). After a 2-week washout period on placebo, each patient received propranolol (80 mg/day), oxprenolol (80 mg/day), atenolol (100 mg/day), and celiprolol (200 mg/day) for 1 week, according to a randomized, cross-over design. At the end of the washout and of each treatment period, airway function, assessed by FEV₁, FVC, and FEV₁%, was evaluated by spirometry both in the basal condition and after salbutamol inhalation. Unlike propranolol and oxprenolol, which significantly reduced FEV₁ and inhibited the bronchdilator response to inhaled salbutamol, atenolol and celiprolol did not significantly affect respiratory function and did not antagonize salbutamol effects. Celiprolol more closely approached placebo in its respiratory effects than did atenolol, although the differences were not statistically significant.     

Pentazocine overdose

A patient who ingested 1.5 g pentazocine developed status epilepticus, coma, respiratory depression, acidosis, profound hypotension, and ventricular arrhythmias. Although this patient survived after institution of general supportive measures, she did not respond to usual doses of naloxone. We describe the clinical symptoms and course of recovery of a patient with pentazocine overdose. Our case suggests that pentazocine overdose may require higher doses of naloxone (5 to 20 mg) than are customarily used for narcotic overdoses.     

Baclofen overdose

Reported is a case of baclofen overdose in a 23-year-old woman. The patient manifested typical symptoms of baclofen overdose, including hypotonia, respiratory depression, and seizures. She was treated successfully with positive pressure ventilation, sedation, and intravenous antibiotics, and was discharged from the hospital on the 14th day following admission with no residual neurological signs, to be followed up in medical and psychiatric outpatient clinics. As baclofen becomes increasingly popular in the treatment of muscle spasm in certain neurological disorders, its availability for misuse increases.     

Effects of atenolol in patients with reciprocating supraventricular tachycardia

We studied 12 patients with crisis of paroxysmal reciprocating supraventricular tachycardia before and after intravenous injection of 5 mg of atenolol. The patients were then followed for periods ranging from 6 to 50 months (median 34 months). During this time, they received oral atenolol therapy, at 200 mg for the first two weeks, and 100 mg daily thereafter. Tachycardia was due to reciprocation within the atrioventricular node in 9 patients, and to pre-excitation in 3 patients. Atenolol slowed the sinus rate, prolonged the atrioventricular conduction time, and increased the atrial cycle length at which atrioventricular nodal Wenckebach phenomenon occurred. During the tachycardia, atenolol increased the tachycardia During the tachycardia, atenolol increased the tachycardia cycle length, due to prolongation of the intranodal atrioventricular conduction time. Of the 11 patients who were observed for the full period, 7 had no further episodes of arrhythmia. One patient (with left-sided pre-excitation) failed to respond to any antiarrhythmic medication, one patient remained free of symptoms for two years, but received an atrial pacemaker for control of the tachycardia at the end of this period. Two patients (one with dual atrioventricular nodal pathways, and one with concealed left-sided pre-excitation) await other treatment for their tachycardia, after remaining free of symptoms for one and two years, respectively. These findings suggest that atenolol is an effective beta blocker for use in controlling arrhythmias in patients with reciprocating supraventricular tachycardia, for use in once daily dosage, and is a medication largely free of side effects.