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 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

2 aspects of oral contraception (OC) were considered--the risk of arteriosclerotic cardiopathy and the interaction with other drugs. Opinions still diverge on the role of contraceptives in the etiology of myocardial infarction. In contrast to the British studies, the World Health Organization's (WHO) data and US statistics on death from cardiovascular diseases fail to show higher prevalence for OC users. Most likely the data of different countries cannot be compared due to the differing incidence of other cardiovascular morbidity and mortality risk factors such as hypertension, obesity, smoking, physical activity, and genetic predisposition. A recent study examined the prevalence of myocardial infarction in relation to the use of estroprogestinic contraceptives. Rosenberg et al. found that 156 out of 121,944 women (1.2%) had been hospitalized following myocardial infarction, and 23 of them used OCs. The authors concluded that OCs increased the risk of infarction by 1.8. Shapiro et al. studied 369 patients who suffered myocardial infarction and an adequate control group. The overall relative frequency was 4 times in OC users but it was 4.5 times in smokers and 3.9 times in nonsmokers. The smokers who did not use OCs showed a relative frequency of 7.8 times. The risk of arteriosclerotic cardiopathy depends upon the dose of both the estrogenic and progestinic components. When prescribing drugs, physicians should know whether their patients use OCs, since these hormonal steroids may interfere with the expected therapeutic effect. A phenomenon of enzymatic competition may occur which slows down the elimination of the drug, thus exposing the patient to a "relative overdose" despite the assumption of therapeutic doses. It has always been reported that the simultaneous administration of triacetiloleandomycin and OCs causes jaundice. Thus far 15 cases have been reported. OCs tend to enhance the effect of corticosteroids. Vitamin K antagonists, oral anticoagulants, are less effective in OC users. A research study conducted by Patwardhan et al. showed that caffeine is eliminated more slowly in OC users because of a mechanism of enzymatic competition with contraceptive steroids at the level of the hepatic oxygenase system linked to cytochrome P-450. ready been reported that the simultaneous administration of triacetiloleandomycin and OCs causes jaundice. Thus far 15 cases have been reported. OCs tend to enhance the effect of corticosteroids. Vitamin K antagonists, oral anticoagulants, are less effective in OC users. A research study conducted by Patwardhan et al. showed that caffeine is eliminated more slowly in OC users because of a mechanism of enzymatic competition with contraceptive steroids at the level of the hepatic oxygenase system linked to cytochrome P-450.
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PMID:Two problems in oral contraception: arteriosclerotic cardiopathy and drug interactions. 716 61

Twenty normotensive and ten hypertensive black women taking oral contraceptive (OC) were studied. Age, body weight, family medical history of hypertension, length of OC use, and type of OC were comparable. At midcycle approximately 10-12 hours following OC intake, blood was drawn and the plasma was used to determine ethynylestradiol (EE2), caffeine, aldosterone (Aldo) and desoxycorticosterone (DOC) levels. The results showed that in hypertensive OC users, EE2 and caffeine levels were significantly higher (P less than .01) compared to normotensive OC users. While no significant differences were found in Aldo and DOC levels between hypertensive and normotensive OC users, OC users had higher levels of Aldo (P less than .01) compared to non-OC users.
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PMID:Blood levels of ethynylestradiol, caffeine, aldosterone and desoxycorticosterone in hypertensive oral contraceptive users. 728 80

We designed the present study to determine whether Ca2+ release from intracellular stores contributes to flow-induced contraction. We carried out experiments on segments of rabbit facial vein under isometric conditions. Intraluminal flow by perfusion of physiological salt solution (10 to 80 microL/min) caused contraction in this vessel, which was significantly inhibited by (1) 30-minute pretreatment with 10 mumol/L ryanodine, the sarcoplasmic reticulum Ca2+ channel opener, and (2) 30-minute pretreatment with concomitant application of 20 mmol/L caffeine and 1 mumol/L cyclopiazonic acid in Ca(2+)-free medium to deplete the sarcoplasmic reticulum. In comparison, contraction initiated by 300 nmol/L histamine was significantly attenuated by the same interventions. K+ (25 mmol/L)-induced contraction was unaffected by ryanodine but was reduced after depletion of the sarcoplasmic reticulum. The phospholipase C inhibitor 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate (10 mumol/L) inhibited contractions induced by flow and histamine but not by K+. These findings indicate that Ca2+ release from intracellular stores, presumably via the phosphatidylinositol pathway, contributes to flow- and histamine- but not raised K(+)-induced contractions in this vessel.
Hypertension 1995 Dec
PMID:Intracellular Ca2+ release in flow-induced contraction of venous smooth muscle. 749 66

Studies have shown that angiotensin-converting enzyme (ACE) inhibitor treatment in young genetically hypertensive rats prevents the full expression of blood pressure and vascular abnormalities in the adult. This model provides unique conditions with which to study the pathogenesis of altered Ca++ regulation. Normotensive (WKY) rats and stroke-prone spontaneously hypertensive rats (SHRSP) received at 6 to 10 weeks of age either ACE inhibitor (ramipril), hydralazine/hydrochlorothiazide or no treatment. At 17 weeks of age, rats were anesthetized, and vascular tissue was excised. Thoracic aorta challenged with 20 mM caffeine in Ca(++)-free buffer produced a phasic contractile response. The magnitude of this phasic response was used as a measure of Ca++ released from intracellular stores; a direct correlation between this phasic response and systolic blood pressure was observed. A concentration-response curve to Bay K8644 was performed on carotid arteries; a direct correlation of force development to Bay K8644 and systolic blood pressure was observed. All WKY groups showed lower blood pressure and force development in response to Bay K8644 than did SHRSP. Treatment with ramipril reduced blood pressure and force development in response to Bay K8644 in adult SHRSP, although not to levels of WKY rats, whereas WKY rats were unaffected by treatment. These data support the hypothesis that contractile responses to Bay K8644 in carotid arteries and caffeine in aorta parallel changes in systolic blood pressure. We conclude that alteration of Ca++ regulation in hypertension is directly related to elevated blood pressure and mediated by an angiotensin II-sensitive mechanism during development.
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PMID:Angiotensin-converting enzyme inhibition during development alters calcium regulation in adult hypertensive rats. 750 33

Sumatriptan is a potent and selective agonist at a vascular serotonin1 (5-hydroxytryptamine1; 5-HT1) receptor subtype (similar to 5-HT1D) and is used in acute treatment of migraine and cluster headache. Following administration of sumatriptan 100mg orally, relief of migraine headache (at 2 hours) was achieved in 50 to 67% of patients compared with 10 to 31% with placebo in controlled clinical trials. In a comparative study, oral administration of sumatriptan 100mg consistently achieved significantly greater response rates than a fixed combination of ergotamine 2mg plus caffeine 200mg during 3 consecutive migraine attacks (66 vs 48% for first attack). Oral sumatriptan 100mg was also more effective than aspirin 900mg plus metoclopramide 10mg orally in a similar study. In the majority of controlled clinical trials, headache relief (at 1 hour after administration) was achieved in 70 to 80% of patients with migraine receiving sumatriptan 6mg subcutaneously compared with 18 to 26% of placebo recipients. Approximately 40% of patients who initially responded to oral or subcutaneous sumatriptan experienced recurrence of their headache, usually within 24 hours, but the majority of these patients responded well to a further dose of sumatriptan. Patients with cluster headache were treated for acute attacks with sumatriptan 6mg subcutaneously or placebo in 2 crossover trials. Headache relief was achieved within 15 minutes in 74 and 75% of patients receiving sumatriptan in these studies compared with 26 and 35%, respectively, with placebo. Patients receiving sumatriptan 12mg had a similar response rate as those receiving 6mg, but the higher dose was associated with an increased incidence of adverse events. Based on extensive safety data pooled from controlled clinical trials, sumatriptan is generally well tolerated and most adverse events are transient. The most frequently reported adverse events following oral administration include nausea, vomiting, malaise, fatigue and dizziness. Injection site reactions (minor pain and redness of brief duration) occur in approximately 40% of patients receiving subcutaneous sumatriptan, although the incidence appears to be markedly reduced when patients self-administer the drug with an auto-injector. Chest symptoms (mainly tightness and pressure) occur in 3 to 5% of sumatriptan recipients, but have not been associated with myocardial ischaemia except in a few isolated cases. Sumatriptan is contraindicated in patients with ischaemic heart disease, angina pectoris including Prinzmetal (variant) angina, previous myocardial infarction and uncontrolled hypertension, but is not contraindicated in patients with migraine and asthma. Data from long term studies in acute treatment of migraine and cluster headache suggest that sumatriptan remains effective and well tolerated over several months.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Sumatriptan. A reappraisal of its pharmacology and therapeutic efficacy in the acute treatment of migraine and cluster headache. 751 61

There is a strong association between cigarette smoking and accelerated hypertension. In mild hypertension smoking cigarettes has a distinct pressor effect and caffeine a small but more prolonged pressor action. Coffee and cigarette smoking together have an additive effect on blood pressure (BP). We have examined the interaction of cigarette smoking and drinking coffee on the BP of six patients who presented with accelerated hypertension (mean BP 240/140 mm Hg) and were heavy smokers and caffeine users. After initial control of the BP, the effects of smoking alone, coffee plus smoking, and placebo were examined in a balanced cross-over study. Baseline BP averaged 154/91 mm Hg and remained stable for 90 min after abstention from smoking and caffeine (placebo). Cigarette smoking without caffeine caused a modest rise in BP (mean 9/8 mm Hg), but the combination of coffee plus cigarette smoking caused a progressive increase in BP to an average 21/17 mm Hg (P < 0.05/P < 0.002) higher than placebo values. The effect of coffee was significantly additive to that of smoking alone. Smoking plus coffee ingestion shifted the BP from acceptable (155/94 mm Hg) to poor control (175/107 mm Hg). This pressor effect was observed despite treatment, and with amounts of caffeine and cigarettes which were in no way unusual for these patients. We propose that the association of cigarette smoking with accelerated hypertension may reflect an extreme pressor effect of combined smoking and caffeine use in some patients.
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PMID:Effect of coffee and cigarette smoking on the blood pressure of patients with accelerated (malignant) hypertension. 775 80

A 48-year-old male patient, a surgeon, displayed a right temporo-occipital cerebral haematoma (5 x 7 cm). He had a history of chronic left occipital migraine-like cephalalgia from the age of 16 and hypertension was diagnosed when he was 42 years old. As therapy, he used ACE inhibitors, nifedipine and clonidine for hypertension and for cephalalgia a combination of aspirin, phenacetin and caffeine. During the last 2-3 months before the detection of cerebral haematoma, injections with piritramide were made when severe headaches were unbearable. The patient was operated on the 7th day since the onset of cerebral haematoma after a "wait and see" period of repeated clinical and CT-scan assessment. The initial option of the patient was surgical. We consider that the patient's profession (medical/surgical profile) may have played a positive motivation for the surgical option.
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PMID:Option for surgical management of cerebral haematoma: case report. 777 46

We have previously demonstrated that alcoholics with transitory (< 72 hr) elevations in blood pressure (BP) during withdrawal continue to show residual cardiovascular dysregulation up to 4 weeks of abstinence. The present study replicates and extends these findings. Alcoholic inpatients were divided into three subgroups (ns = 14) based on BP during the first 72 hr of withdrawal: transitory hypertensives (tHTs; BP > 160/95 mm Hg), transitory borderline hypertensives (tBHs; 140/90 < or = BP < 160/95), and normotensives (NTs; all BPs < 140/90). All patients had normal resting pressures after 72 hr of withdrawal. At 3-4 weeks postadmission, the alcoholics and 14 nonalcoholic controls (CONTs) were tested at rest and during a 5-min handgrip task. The tHTs showed an exaggerated systolic and diastolic BP response to handgrip compared with NTs and CONTs, with tBHs intermediate (ps < 0.05). Drinking history showed the tHTs had the highest reported level of alcohol consumption and severity of withdrawal symptoms (ps < 0.05). Regression analyses indicated that consumption of hard liquor was the variable most predictive of admission BPs; further, parental history of hypertension potentiated this relationship for systolic BP. Age and consumption of nicotine and caffeine were not significant predictors of admission BP. The results suggest a persistent cardiovascular dysregulation in alcoholics showing transient hypertensive withdrawal BPs. These alcoholics may be at increased risk for future alcohol-related cardiovascular disorder.
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PMID:Drinking history is related to persistent blood pressure dysregulation in postwithdrawal alcoholics. 784 2

The relationship between consumption of decaffeinated coffee and acute myocardial infarction was analyzed in a case-control study conducted in Italy between 1983 and 1992. Case patients were 433 women with acute myocardial infarction, aged 24 to 69 years (median age, 52 years), and control subjects included 869 women in hospital for a wide spectrum of acute conditions, other than cardiovascular, neoplastic, digestive, and hormone-related diseases or conditions associated with long-term modification of diet. Regular use of decaffeinated coffee was reported by 11% of the case patients and 7% of the control subjects. Compared with women who did not drink decaffeinated coffee, the relative risk (RR) was 1.3 (95% confidence interval (CI), 0.8 to 2.2) for one cup/d and 2.1 (95% CI, 1.1 to 3.9) for 2 or more cups (chi 2(1) for trend = 5.62, P = 0.02). The estimates were somewhat higher after allowance for education, marital status, body mass index, and smoking status (RR for > or = 2 cups of decaffeinated coffee per day, 2.5; 95% CI, 1.2 to 4.9), and somewhat lower after further allowance for diabetes, hypertension, and hyperlipidemia (RR, 1.7; 95% CI, 0.8 to 3.6). There was no association between duration of use of decaffeinated coffee and infarction risk. The relationship between decaffeinated coffee and infarction was consistent across strata of age, education, smoking, and history of hyperlipidemia. Thus, a relationship of marginal significance was observed in this study between decaffeinated coffee and myocardial infarction, of similar magnitude to that described for caffeinated coffee. This indicates that (i) caffeine is unlikely to be a relevant factor in any potential coffee-myocardial infarction relationship, and (ii) shifting from caffeinated to decaffeinated coffee is unjustified in order to reduce any possible coffee-related infarction risk.
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PMID:Decaffeinated coffee and acute myocardial infarction. A case-control study in Italian women. 792 7

In the present study we used radiotelemetry technology to investigate: 1) the time course for development of hypertension in 2-kidney, 1-clip (2K1C) rats and 2) the effect of chronic caffeine consumption on blood pressure in 2K1C rats. Rats received water or caffeine (0.1%) in drinking water and were instrumented with radiotelemetry devices to permit continuous monitoring of blood pressure. A clip was placed on the left renal artery of rats in both the water (WATER/CLIP) and caffeine (CAFFEINE/CLIP) groups. The clip was applied briefly to, then removed from, the renal artery of caffeine- and water-treated rats randomized to the sham-operated (SHAM) group. Mean arterial blood pressure (MABP) increased by approximately 35 mm Hg within 2 hr of clipping. MABP in the WATER/CLIP and CAFFEINE/CLIP groups differed significantly from the SHAM group, but not from each other, for the first 10 days after clipping. Thereafter, MABP was greater in the CAFFEINE/CLIP rats as compared to WATER/CLIP rats. At 4.5 weeks after clipping, MABP values differed significantly in the CAFFEINE/CLIP, WATER/CLIP and SHAM rats (140 +/- 4, 122 +/- 4 and 103 +/- 2 mm Hg, respectively). Involvement of the renin-angiotensin system was assessed by treatment with the AT1 receptor antagonist, losartan, and the converting enzyme inhibitor, captopril. Results from this study indicate: 1) hypertension develops rapidly after clipping in rats monitored with telemetry; 2) the renin-angiotensin system is involved in maintaining hypertension in 2K1C rats even beyond 4 weeks after clipping; and 3) caffeine augments the increase of blood pressure in 2K1C rats, apparently through the involvement of the renin-angiotensin system.
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PMID:Telemetric blood pressure monitoring in benign 2-kidney, 1-clip renovascular hypertension: effect of chronic caffeine ingestion. 793 54


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