Excess synthroid ingestion presenting as congestive heart failure.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
R W Piepho
Publications and source records attributed to R W Piepho.
Antihypertensive therapy in the aged patient. Clinical pharmacokinetic considerations.
The incidence of both systolic and diastolic hypertension is increased in elderly patients, therefore antihypertensive drugs are commonly used in this population. In addition to changes in blood pressure, the aging process also causes numerous changes in other physiological parameters, resulting in altered pharmacokinetic and pharmacodynamic responses to the drugs. The dosage regimens for thiazide diuretics and amiloride must be individually titrated in the elderly patient, since the elimination of these agents decreases concurrently with decreased renal function, as indicated by compromised creatinine clearance. The initial doses of the calcium antagonists should be decreased in elderly patients, since representative compounds from all 3 chemically heterogeneous classes have been shown to have decreased clearance in these patients which appears to be primarily due to the status of hepatic function in the patient. However, with verapamil, the dosage should be further decreased in association with compromised renal function. The dosage of the angiotensin converting enzyme (ACE) inhibitors should be adjusted according to renal function rather than age. Lisinopril, which is primarily eliminated unchanged, is usually given in lower doses in the elderly, and doses of both captopril and enalapril may need to be reduced, depending on renal function. While there is no need to adjust the dosage regimen for the alpha-adrenoceptor blocking drugs (prazosin, terazosin), caution should be used with the beta-adrenergic blockers, particularly the hydrophilic agents, since they are renally eliminated. Labetalol may be a suitable alternative beta-blocker for the elderly patient, since its pharmacodynamic properties of decreased systemic vascular resistance without changes in heart rate or stroke volume are preferential for the elderly patient, and its pharmacokinetics are relatively unchanged in this population. Drugs that act primarily through the central nervous system, such as clonidine, methyldopa and guanfacine, require smaller doses in the presence of renal dysfunction. In contrast, guanabenz is metabolised primarily by the liver, so it would appear to be useful in elderly patients with renal dysfunction despite the lack of studies in this population. Guanadrel, an adrenergic neuron blocking drug, also requires a dosage reduction in patients with impaired renal function. In addition to the pharmacokinetic changes that occur in the elderly patient, pharmacodynamic changes may also be anticipated due to receptor modifications. Older patients have a decrease in beta-receptor sensitivity, while alpha-receptor sensitivity does not change. When designing the dosage regimen for a senior patient with hypertension, the combination of all these variables must be considered.
Adrenergic alpha-Antagonists↗
Antihypertensive therapy in the geriatric patient. I: A review of the role of calcium channel blockers.
Animal and clinical studies have demonstrated the efficacy of calcium channel blockers in reducing blood pressure, especially in older patients whose hypertension is characterized by increased peripheral vascular resistance. Their chemical heterogeneity, which permits targeted therapy, as well as their minimal side effects, drug interactions, and clinical utility in numerous pathophysiologic states common to the elderly, enhance the suitability of calcium channel blockers in treating mild to moderate hypertension in this subgroup. This is particularly relevant for those patients who have concomitant conditions, such as diabetes, chronic obstructive pulmonary disease, or peripheral vascular disease, and for whom many of the more traditional antihypertensive drugs are either contraindicated or might cause a worsening of the disease.
Aged↗
Drug interactions with the calcium-entry blockers.
The increasing use of the calcium-entry blockers has led to an enhanced potential for drug interactions with a variety of different drugs. Interactions with cardiovascular agents are of great concern because of the consequences of synergistic negative dromotropism or inotropism. We therefore assessed the concomitant use of calcium-entry blockers and cardiac glycosides, beta-blockers, antiarrhythmic agents, and other chemical types of calcium-entry blockers from a standpoint of clinical relevance. We also evaluated reported drug interactions with H2-receptor antagonists, anticonvulsants, lithium carbonate, general anesthetics, cytostatic drugs, rifampin, and sulfinpyrazone with regard to clinical implications, along with the modification of calcium-entry blocker dose for concurrent social drug use, such as cigarette smoking and ethanol intake. Although a myriad of potential drug interactions exists for these agents, combination therapy is still a reasonable alternative if doses are adjusted appropriately.
Adrenergic alpha-Antagonists↗
Acute effects of increasing doses of urapidil in patients with hypertension.
In a randomized, double-blind, dose-ranging trial, the acute antihypertensive effects of 7.5, 15, 30, 45, 60, 90, and 120 mg single daily doses of urapidil were compared with those of placebo in 10 patients with essential hypertension. Patients were randomized to either urapidil or placebo, such that each active drug day was followed by a placebo washout day. Blood pressure and heart rate responses were measured in the supine position, immediately upon standing, and after 3 to 5 minutes of standing for each dose. A variable but significant reduction in systolic and diastolic blood pressures that lasted from 4.5 to 8 hours was observed primarily at the 60, 90, and 120 mg doses (P less than 0.05). The maximum reduction in diastolic blood pressure occurred in the standing position at 3 to 5 hours after dosing. When urapidil was compared with placebo, a change from the supine to the standing positions produced a significantly larger reduction in systolic and diastolic blood pressures (P less than 0.05) but no significant change in heart rate. This suggests an acute blood pressure lowering effect of urapidil that occurs predominantly in the standing position and that does not significantly increase heart rate.
Adult↗
Management of dental pain in the elderly.
Explore the source record for details and available documents.
Aged↗
Effect of photoperiod reversal on twenty-four hour patterns for dopamine levels in the corpus striatum and upper and lower brainstem of the rat.
Dopamine levels were measured in the corpus striatum, upper and lower brainstem at 6 hour intervals for a period of 24 hours in rats adapted for 3 weeks to either of two concomitantly-conducted lighting programs. On the normal cycle the animals were illuminated from 08(00)--20(00); on the reverse cycle, from 20(00)--08(00). In the corpus striatum dopamine levels peaked during the dark phase of both illumination cycles indicating that 24 hour rhythm is exogenous. On the other hand, in the upper and lower brainstem, dopamine peaks occurred in both light cycles at 00(00) or 06(00) indicating that these 24 hour rhythms are endogenous in nature. Photoperiod reversal resulted in significantly elevated dopamine levels in the corpus striatum and lower brainstem. The existence of a stress as well as a seasonal factor which affects striatal dopamine is suggested.
Animals↗
Pharmacists' knowledge and attitudes regarding monitoring the behaviors of children with learning disabilities.
The attitudes and knowledge of pharmacists in Nebraska regarding children's learning disabilities were surveyed by questionnaire. One hundred thirty-three pharmacists responded. The results were analyzed according to type of practice (community, chain and hospital) and age (20--30 years, 31--40 years, 41--50 years, and 51 years and over). The results indicate that pharmacists are being asked about learning disabilities. Overall, 53% of the pharmacists responding had been asked about learning disabilities by parents, physicians, teachers or others. No significant interactions were found between the type of practice and age, and no significant main effect for type of practice was found in the ANOVA results for knowledge scores or attitude scores. Even though there were no differences owing to age in pharmacists' knowledge of learning disabilities, age was found to have a significant effect on attitudes toward increased pharmacist involvement in monitoring behaviors of learning-disabled children; the younger groups had a more positive attitude. The pharmacist seems to have the knowledge and attitudes required to become more actively involved in monitoring the medications and behaviors of children with learning disabilities.
Adult↗
Effect of photoperiod reversal on twenty-four hour patterns for GABA levels in rat brain.
GABA levels were measured in various areas of rat brain at 3 or 6 hour intervals for a period of 24 hours in animals adapted for 3 weeks to a programmed-lighting schedule. On the normal cycle rats were illuminated from 08 to 20 hours; on the reverse cycle, from 20 to 08 hours. The cerebellar pattern is unimodal with a peak in the dark at 06 hours and a trough in the light at 18 hours which coincides with maxima and minima of motor activity in the nocturnal rat. The cortical pattern also peaks in the dark at 06 hours but is less well-defined. On the reverse illumination cycle both patterns peak significantly in the dark at 18 hours. Only the cerebellum displays significant differences when averaged GABA levels for light and dark phases are compared. A circadian pattern peaking in the dark described for GABA levels of the corpora quadrigemina which is partly-reversed by reversing the photoperiod. The rhythm in thalamus-hypothalamus which peaks in the dark is complex, consisting of an ultradian rhythm super-imposed on a circadian one. The former rhythm appears to be endogenous and unaltered by a change in the illumination cycle; the latter exogenous since it varies with the illumination cycle. Lower GABA levels in rat brain were found after photoperiod reversal.
Animals↗
Minimal brain dysfunction.
Explore the source record for details and available documents.
Anti-Anxiety Agents↗
Hypothermic response following administration of 2-amino-4-pentenoic acid (allylglycine).
Intraperitoneal administration of allylglycine resulted in a hypothermic response in rats. At a dosage of 90 mg/kg, a significant decrease in temperature was noted at 4 and 8 hr after administration, but no significant difference was noted at 12 hr. The same dose administered intraperitoneally to decapitated rats did not result in a hypothermic response, and intraventricular administration resulted in a rapid onset of hypothermia after 1 hr. These findings are indicative of a central site of action for the allylglycine-induced hypothermia. Quantitative assay of hypothalamic monoamines (norepinephrine, serotonin, and dopamine) did not show any significant changes at 4, 8, and 12 hr postadministration when compared to controls. A significant decrease in hypothalamic gamma-aminobutyric acid was noted at each of these time points when compared to controls. These data suggest an important role for gamma-aminobutyric acid in mammalian thermoregulatory control.
Allyl Compounds↗
A comparison of the inductive effects of phenobarbital, methaqualone, and methyprylon on hepatic mixed function oxidase enzymes in the rat.
The effects of equal doses of three sedative-hypnotics, phenobarbital, methaqualone, and methyprylon, on the hepatic mixed function oxidase enzymes of the rat were investigated and compared. After 5 days of pretreatment, phenobarbital and methyprylon significantly increased aminopyrine demethylation, aniline hydroxylation, and cytochrome P-450 content in hepatic microsomes. Methaqualone pretreatment only increased hepatic aminopyrine demethylase activity and wet liver weights. After 29 days of pretreatment, phenobarbital significantly increases aminopyrine demethylase, aniline hydroxylase activity, liver weight and cytochrome P-450 content. Methaqualone only produced a significant increase in wet liver weight.
Animals↗
Chronopharmacology of strychnine and allylglycine in the mouse.
1. The response of individually caged mice to the lethal actions of allylglycine and strychnine was evaluated in animals previously conditioned on an LD 12:12 (12 h light-12 h darkness) schedule in a controlled environment. 2. These convulsant agents were most toxic at 18.00 hours (during the light phase), and least toxic in the dark phase of the programmed lighting schedule. The relationship is considered of the circadian fluctuations in levels of inhibitory transmitter substances to the time-linked action of convulsant agents.
Animals↗