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Biomedical subjects

F Follath

Publications and source records attributed to F Follath.

At least 217 records · Page 12Linked to original sources
PubMed1981

[Side effects of drugs in the geriatric patient (author's transl)].

The probability of experiencing adverse drug reactions increases with age. Polypharmacy, pharmacokinetic changes (altered drug distribution, reduced renal and hepatic drug clearances), unusual pharmacological effects and impaired compensatory mechanisms are the principal reasons for the diminished tolerance of elderly patients to several drugs. Especially neuroleptics, antidepressants, tranquilizers, digoxin, potent diuretics, betablockers, and antiarrhythmics have to be employed with special care. To prevent adverse reactions in geriatric patients, prescriptions should be limited to a few essential drugs, dosage reduced, and dosing regimens simplified. However, therapeutic nihilism can never be justified by old age alone.

Acute Kidney Injury↗
PubMed1980

[Serum concentration measurements for the monitoring of anti-arrhythmic therapy with lidocaine].

Repeated measurements of lidocaine serum levels during antiarrhythmic treatment were performed by enzyme-immunoassay (EMIT) in 16 patients with acute myocardial infarction. In 12 cases the frequently employed standard dose (100 mg i.v. followed by infusion of 2 mg/min) was not sufficient to reach optimum lidocaine (2-5 mg/l) during the first 2 hours. In this period 6 patients had persistent ectopic beats and required additional bolus injections and increased infusion rates. Lidocaine elimination was delayed in patients with heart failure, which led to potentially toxic drug accumulation in 3 instances. This study indicates the need for individual adaptation of lidocaine dosage in patients with myocardial infarction, especially where left ventricular function is impaired. Monitoring of serum lidocaine levels by a rapid and reliable assay such as the EMIT system may greatly facilitate this task.

Adult↗
PubMed1980

Nomographic estimation of time to reach steady-state serum concentration during phenytoin therapy.

The time to reach steady-state on phenytoin therapy depends on the dose and the pharmacokinetic parameter of the individual patient. A nomogram is presented to help the physician to decide whether a measured serum concentration of phenytoin can be regarded as being within 20% of the steady-state level. The nomogram is based on the pharmacokinetic parameters of phenytoin reported for adult patients.

Humans↗
PubMed1980

Rapid prediction of steady-state serum theophylline concentration in patients treated with intravenous aminophylline.

In 15 acutely ill asthmatics the steady-state serum theophylline concentration was predicted by the method of Chiou et al. using two serum concentration measurements obtained 1 and 5 h after starting a continuous infusion of aminophylline. Two theophylline assays with different precision characteristics were compared. With a precise HPLC-assay the prediction was excellent: prediction error (predicted minus measured concentration) = -0.22 +/- 1.97 mg/l (mean +/- SD); r = 0.922. When the theophylline concentration was determined by a rapid enzyme immunoassay of lower precision, but convenient for clinical use, the prediction was less accurate (prediction error = 0.58 +/- 3.88, r = 0.852). However, it was still clearly superior to dosing recommendations based on the population average of theophylline clearance, even after taking into consideration the effect of smoking, congestive heart failure and cirrhosis (prediction error = 3.62 +/- 13.36, r = 0.560). As employed in this study, the method may be useful in helping the physician to choose the optimal dose in severely ill asthmatics.

Aminophylline↗
PubMed1980

Predictability of phenytoin serum levels by nomograms and clinicians.

On the basis of a reliable steady state phenytoin serum concentration on one (lower) dose, the serum concentration on a second (higher) dose was predicted in 28 patients (32 levels) by two previously reported nomograms and 3 physicians who had clinical experience with phenytoin therapy. Both nomograms and all 3 physicians on the average underestimated the serum concentration on the higher dose. Except for 1 physician, this bias was statistically significant (p < 0.05). The mean and SD of the prediction errors (difference between predicted and measured serum concentration) were -2.2 +/- 4.2 and -3.1 +/- 3.6 for the two nomograms and -1.0 +/- 4.0, -2.1 +/- 4.1 and -1.8 +/- 4.2 for the 3 physicians, respectively. Thus, independent of the method used, there was a large uncertainty in the prediction; the approximate 68% confidence interval of the prediction error (mean +/- SD) was almost as large as the therapeutic range of the drug. Because prediction of phenytoin serum levels based on one serum concentration measurement was found unreliable in this study, it is proposed that every patient whose dose had been increased should be under close observation until a new steady state has been confirmed.

Adult↗
PubMed1980

[Comparison of methods of determination of serum doxycyline assessing relative bioavailability of two commercial formulations (author's transl)].

The present study was undertaken to evaluate the accuracy of the analytical results of an investigation of relative bioavailability of two doxycycline preparations. Six methods in four laboratories were applied: one fluorimetric, three high-pressure-liquid-chromatographic and three microbiological methods. The analyses were performed after coding the samples. In all cases the two preparations were bioequivalent. When comparing the methods, it could be shown that the fluorimetric method was slightly more accurate than the others. The HPLC-methods were almost as accurate. The results of the microbiological determinations showed the lowest accuracy. Two of the results were in good agreement with the biochemical methods, whereas the third showed such a high deviation that a comparison was no longer possible. Altogether a good agreement of all compared methods (except one) could be demonstrated.

Biological Assay↗
PubMed1979

[Delayed elimination of aminoglycoside antibiotics: importance for clinical use].

In 7 patients the elimination of amikacin (4), tobramycin (1) and gentamicin (2) in serum and urine was measured over several days after cessation of therapy. All three aminoglycosides showed multicompartmental pharmacokinetics with a terminal half life ranging between 46 and 150 hours. Using computer simulations, it is shown that slow drug accumulation in the body is to be expected during multiple dose therapy. Therefore, the indiscriminate use of these drugs should be avoided and the duration of therapy kept as short as possible.

Amikacin↗
PubMed1979

[Cardiac tamponade in malignant tumors].

Among 40 patients with cardiac tamponade observed over the years 1972--1978, 23 (57.5%) had a neoplasm as primary cause of illness. The most common etiology was bronchial carcinoma (13). In 9 cases cardiac tamponade was the first clinical symptom of the tumor. Evacuation of the pericardial fluid by puncture (3), surgical drainage (6) and left parasternal insertion of a plastic catheter (12) brought rapid relief from symptoms in all cases. Six patients survived 3--6 months, while another two have now been followed up for over 5 years. Diagnostic problems and therapeutic possibilities in malignant pericarditis are discussed.

Adult↗
PubMed1979

Multicompartment pharmacokinetics of netilmicin.

The pharmacokinetics of a single dose of netilmicin (NM) was studied in 6 healthy volunteers. Elimination of the drug was followed in serum and urine for 24 h and 72 h, respectively. NM concentrations were measured with a modified radioenzymatic assay. A three compartment open model was employed to calculate the pharmacokinetic parameters. Following the rapid initial distribution, biphasic elimination with half lives of 1.99 (t 1/2 beta) and 36.89 h (t 1/2 gamma) was demonstrated. Measurable amounts of NM were excreted in the urine for up to 72 h. The volume of distribution at steady-state (Vdss) of 0.68 l/kg was 3 to 4 times larger than previously reported for this antibiotic. NM plasma clearance was 91 ml/min and the renal clearance was 67 ml/min. The data indicate that on repetitive dosing the amount of drug in the body would be considerably underestimated if the prolonged terminal elimination phase were not taken into account. During prolonged treatment, accumulation of NM in renal and other tissues is likely to occur, as has been described for other aminoglycosides. The possible consequences of this pharmacokinetic behaviour are discussed.

Adult↗
PubMed1979

Progression of mild mitral stenosis and incidence of restenosis after open commissurotomy: a study using echocardiography.

Thirteen patients with mild mitral stenosis and 21 asymptomatic patients after commissurotomy were studied by echocardiography in order to assess the rate of progression of mitral stenosis and the incidence of restenosis after successful open mitral commissurotomy. In the group with mitral stenosis there was a decrease of the diastolic closing velocity (E-F slope) from 35.7 to 29.5 mm./sec. (p less than 0.0005) over a period of 37 months. In 23% of the patients the stenosis increased significantly (p less than 0.0005) by echocardiographic parameters. Forty-eight months after commissurotomy we noted a significant over-all slowing of the diastolic closing velocity (from 52.6 to 44.8 mm./sec., p less than 0.0005) and a decrease of the mitral valve closure index DE/MAIC (from 1.7 to 1.5, p less than 0.0025). Five of 21 patients (24%) showed a change in one or both of these parameters which was greater than 2 standard deviations of the mean change. Based on echocardiographic criteria, we conclude that patients with mild mitral stenosis and asymptomatic patients following successful commissurotomy need only be checked approximately every 3 years.

Adult↗