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Biomedical subjects

J Ahlner

Publications and source records attributed to J Ahlner.

At least 37 records · Page 2Linked to original sources
PubMed1998

Antihypertensive medication in clinical encounters.

In managing hypertension, patient participation and understanding of the nature and significance of treatment are decisive. We analysed the communication between patient and physician with respect to antihypertensive medication at a follow-up appointment, and assessed patients' knowledge of their medication. The empirical data consist of audio-recordings from 51 hypertensive patients' follow-up appointment with their physicians. Thirty-three of these patients were interviewed in depth immediately after the appointment. The study was performed in primary health care centres and at a specialist clinic for hypertension. When discussing medications, patients mainly talked about experiences of being on medication, whereas physicians generally focused on the pharmacological effect and dosage of the drug. Physicians routinely asked about compliance with drug regimen, but seldom in any depth. Little effort was invested into discussing the effect and goal of therapy. The main finding was that patients had a very fragmentary understanding of the functional nature of their antihypertensive medication. This is unsatisfactory both from the point of view of treatment efficacy and also when considering the legal requirements of involving the patient in the decision making. The follow-up appointments studied gave few possibilities for the patient to learn about their antihypertensive medication.

Aged↗
PubMed1998

Perceived symptoms amongst hypertensive patients in routine clinical practice- a population-based study.

OBJECTIVES: To compare perceived symptoms between patients undergoing antihypertensive therapy and hypertensive patients without drug treatment, and to assess reasons for change of antihypertensive medication in routine clinical practice. DESIGN: Population-based multicentre study. Consecutive patients from a randomized sample of centres were given a standardized questionnaire to assess symptoms as well as opinions about their antihypertensive drugs. SETTING: Fifty-five Swedish primary health care centres and 11 clinics of internal medicine. PATIENTS: One thousand and thirteen hypertensive patients on their individually prescribed antihypertensive medication and 13 5 without antihypertensive therapy. MAIN OUTCOME MEASURES: Prevalence and perception of symptoms with and without antihypertensive drug therapy, changes of medication and reasons for this. RESULTS: Amongst the group of patients on antihypertensive medication, 57% spontaneously reported having had symptoms of high blood pressure before they started their drug therapy. Amongst the patients without antihypertensive drugs, 52% reported having such symptoms. When answering direct questions about different symptoms related to current drug treatment or increased blood pressure, patients with and without medication reported symptoms to a similar extent: 80 and 85%, respectively. A majority of patients (64%) had changed their medication during the course of treatment (range 0-61 years). The mean number of changes was 2.4 times over 12 years. The most common reported cause for changing drug treatment was side-effects (42%). CONCLUSIONS: The study shows that patients in general perceive symptoms from hypertension. Antihypertensive medication decreases the frequency and intensity of symptoms that might be related to high blood pressure but adds other symptoms linked to the medication. Changes in medication were mostly related to side-effects. The follow-up should pay attention to patients' experience of treatment. A sign of a well-managed hypertension population would be a decrease of symptoms over time.

Adult↗
PubMed1998

A population-based study of plasma cyclic guanosine monophosphate: relations to age, atrial natriuretic factor and angiotensin-converting enzyme activity.

In order to study the relations between plasma cyclic guanosine monophosphate (cGMP) and anthropometric variables, plasma atrial natriuretic factor (ANP) and serum angiotensin-converting enzyme activity (ACE), a population study with random selection of 217 subjects (49% men) 18-69 years old was performed. Venous blood was drawn at 08.00 h and ambulatory blood pressure (ABP) recording was then performed. There was no gender-difference in cGMP levels (men 2.2 +/- 1.1 nmol L-1, women 2.2 +/- 1.1 nmol L-1). A weak negative correlation was seen between cGMP and systolic ABP in both genders 20-44 years of age (r = -0.3, p = 0.05 for both), but this correlation did not persist in multivariate analysis with correction for ANP, age and ACE. In women, cGMP correlated positively with ANP (r = 0.27, p = 0.005) independently of ANP, ACE, ABP and age. ACE correlated negatively with cGMP in men (all; r = -0.22, p = 0.03, 45-69 years of age r = -0.49, p = 0.0002) and this correlation was independent of ANP, ACE, ABP and age. ACE catalyses the breakdown of bradykinin, which stimulates the release of NO. As the second messenger of NO is cGMP, the negative correlation between ACE and cGMP in men might be a reflection of reduced production of NO. Our results also suggest that there are gender differences in the stimuli for basal cGMP production.

Adult↗
PubMed1998

Cerebrospinal fluid concentrations of propofol during anaesthesia in humans.

The concentration of propofol in and surrounding the human brain during propofol anaesthesia is unknown. We measured simultaneously the concentration of propofol in cerebrospinal fluid (CSF) from an indwelling intraventricular catheter and the concentration in arterial blood in five neurosurgical patients before, during induction (at 2.5 and 5 min) and during a maintenance propofol infusion (at 15 and 30 min). After induction of anaesthesia with propofol 2 mg kg-1, anaesthesia was maintained with an infusion of 8 mg kg-1 h-1 for 15 min and then reduced to 6 mg kg-1 h-1. The plasma concentration of propofol increased rapidly during induction and reached a plateau concentration of mean 2.24 (SD 0.66) micrograms ml-1 after 5 min. The concentration of propofol in CSF showed a slower increase during induction and remained almost constant at 35.5 (19.6) ng ml-1 at 15-30 min after induction. The CSF concentration of propofol that we measured was 1.6% of the plasma concentration and consistent with the high protein binding of the drug in plasma.

Adult↗
PubMed1998

Patients' and physicians' assessment of risks associated with hypertension and benefits from treatment.

BACKGROUND: Perceptions of effects of a medical regimen may affect patients' adherence to therapy. OBJECTIVE: To assess concordance between patients' and physicians' estimations of the risks of hypertension and benefits of treatment during a regular follow-up appointment. DESIGN: A population-based Swedish multicentre study. Patients were included consecutively from a randomized selection of centres (55 primary health care centres and 11 clinics of internal medicine). METHODS: A questionnaire was given to 1013 patients undergoing their individually prescribed antihypertensive therapy and 212 physicians who were caring for these patients. RESULTS: Without therapy, patients perceived the risks of cardiovascular complications to be higher than did their physicians. Patients were not aware that an increasing number of risk factors has an impact on the risk of complications. Patients furthermore rated the benefits of treatment higher than did their physicians (P<0.001). Of the patients, 14% had blood pressures < or = 140/90 mmHg. Most of the patients (61%) were not aware of their target blood pressure. However, when the target pressure was communicated to patients by the physician, patients remembered it accurately. The patients were generally not willing to trade even minor side effects from antihypertensive therapy for benefits of treatment. CONCLUSIONS: There was a high degree of inconsistency between patients' and physicians' estimations of risks of hypertension. Patients estimated the effects of treatment to be more beneficial than did their physicians.

Adult↗
PubMed1997

Seasonal variations in cyclic GMP response on whole-body cooling in women with primary Raynaud's phenomenon.

1. Primary Raynaud's phenomenon (PRP) is characterized by increased vasoconstrictor tone that develops during exposure to cold. The symptoms are most pronounced during the winter months with low outdoor temperature. The L-arginine-nitric oxide (NO)-cyclic GMP (cGMP) pathway plays an important role in counteracting vasospasm. The aim of the present study was to investigate if the venous cGMP response to whole-body cooling in women with PRP varied with the season of the year. 2. The study was performed as an open parallel-group comparison between women with PRP and healthy female controls during the winter months of February 1994 and 1995 and in the summer month of August 1994. Blood samples were drawn just before and 40 min after whole-body cooling. 3. There were no significant changes in venous cGMP after whole-body cooling in women with PRP during the winter months of February 1994 and 1995. Cold exposure in the summer month of August resulted, however, in a significant increase in venous cGMP (P < 0.01). In contrast, the healthy women responded with a significant increase in venous cGMP on all three test occasions: February 1994 (P < 0.05), August 1994 (P < 0.05) and February 1995 (P < 0.01), 4. A seasonal variation in venous cGMP response to whole-body cooling was observed only in women with PRP. Healthy women responded to cold exposure with an increase in venous cGMP during summer and winter, whereas females with PRP showed an increase only during summer. Results from the present study might indicate seasonal variation in the regulation of constitutive nitric oxide synthetase in women with PRP, which may contribute to new therapeutic approaches.

Adult↗
PubMed1997

Plasma nitric oxide metabolite in women with primary Raynaud's phenomenon and in healthy subjects.

Primary Raynaud's phenomenon (PRP) is characterized by cold- or stress-induced transient attacks of impaired skin circulation in fingers and/or toes. PRP displays seasonal variation with less severe symptoms in the summer. The aetiology has not been clarified. The aims of the present study were (a) to assess the influence of cold exposure on the plasma levels of the nitric oxide (NO) metabolite, nitrate, in patients with PRP and in healthy control subjects; and (b) to investigate whether there is a seasonal variation in these plasma levels. In a group of women with PRP and matched control subjects, venous blood was sampled before and at the end of a 40-min period of whole-body cooling. The study was performed with the same protocol on two occasions; once in the winter and once in the summer. A seasonal variation was detected with higher plasma levels of nitrate in the winter than in the summer, both in PRP and in control subjects. However, the plasma level of nitrate was not changed in response to cold exposure on any occasion, either in the patient or in the control group. Our study indicates that NO formation is up-regulated in response to cold weather in both study groups. However, NO formation does not seem to be increased in response to whole-body cooling, either in PRP patients or in healthy subjects. Further investigations are required to reveal whether the observed seasonal variation in NO formation is a universal phenomenon in man.

Adult↗
PubMed1997

Hypertensive patients' knowledge of high blood pressure.

OBJECTIVE: To investigate hypertensive patients' understanding of the circulatory system, in particular high blood pressure. DESIGN: Semi-structured audio-taped interviews of patients immediately after a regular follow-up appointment with their physician. SETTING: A primary health care centre and a specialist clinic (hypertension unit) in southern Sweden. PATIENTS: 33 hypertensive patients, consecutively selected. MAIN OUTCOME MEASURE: Focus was set on the exploration of patients' understanding/knowledge. RESULTS: In spite of a long history of hypertensive care, on average ten years, patients had a less than satisfactory understanding of their condition. Most patients knew their blood pressure values, but very few were able to give an account of what high blood pressure implies in functional terms. Knowledge of high blood pressure seems mainly to be derived from sources other than the health care system, in particular from the mass media. Knowledge of the risks associated with hypertension was quite good, as was the insight into how these risks could be managed. CONCLUSION: An assessment of patient knowledge of high blood pressure ought to be a starting point for educational strategies that aim to deepen patients' understanding of their state of health.

Adult↗
PubMed1997

Fibromyalgia--are there different mechanisms in the processing of pain? A double blind crossover comparison of analgesic drugs.

OBJECTIVE: Pain was analyzed in patients with fibromyalgia (FM) in a randomized, double blind, crossover study using intravenous (i.v.) administration of different drugs. METHODS: In 18 patients with FM muscle pain to i.v. administration of morphine (0.3 mg/kg), lidocaine (5 mg/kg), ketamine (0.3 mg/kg), or saline was studied. Spontaneous pain intensity, muscle strength, static muscle endurance, pressure pain threshold, and pain tolerance at tender points and non-tender point areas were followed. Drug plasma concentrations and effects on physical functioning ability score (FIQ) were recorded. A personality inventory (KSP) was used to related pain response to personality traits. RESULTS: Thirteen patients responded to one or several of the drugs, but not to placebo. Two patients were placebo responders responding to all 4 infusions. Three were nonresponders responding to no infusions. Seven of the responders had a reduction in pain for 1-5 days. Pressure pain threshold and pain tolerance increased significantly in responders. Plasma concentrations were similar in responders and nonresponders. FIQ values improved significantly after the ketamine infusion. Responders scored higher on KSP scales for somatic anxiety, muscular tension, and psychasthenia compared with healthy controls. CONCLUSION: FM diagnosed according to the American College of Rheumatology criteria seems to include patients with different pain processing mechanisms. A pharmacological pain analysis with subdivision into responders and nonresponders might be considered before instituting therapeutic interventions or research.

Adult↗
PubMed1996

Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers.

OBJECTIVE: This study was performed to assess whether coadministration with grapefruit juice significantly affects the pharmacokinetics of amlodipine, a dihydropyridine class calcium antagonist with slow absorption, distribution and low plasma clearance. The primary objective was to evaluate whether short exposure to grapefruit juice could affect the metabolism of amlodipine to an extent similar to that previously demonstrated for other dihydropyridines (e.g. felodipine, nisoldipine, nitrendipine). METHODS: Twelve healthy male volunteers followed a randomised, open crossover study design, comparing the effect of a single oral dose of amlodipine (5 mg) taken together with a glass of grapefruit juice (250 ml) vs water. Blood samples to determine plasma concentration were taken and blood pressure (BP) and heart rate (HR) were measured throughout the study. RESULTS: When amlodipine was coadministered with grapefruit juice, Cmax was 115% and AUC(0-72 h) was 116% compared with water, but tmax was not significantly changed. There were no significant differences in BP and HR between the two treatments. A small decrease in diastolic BP, however, was observed in both treatments 4-8 h after drug administration, coinciding with Cmax, but this was normalised after 12 h. The BP reduction seen was compensated by a slight increase in HR, which remained throughout the study. CONCLUSION: An interaction between grapefruit juice and amlodipine was demonstrated. The haemodynamic data showed that a dose of 5 mg was sufficient to achieve a BP reduction in healthy subjects, but the increase in amlodipine plasma concentration seen after intake of grapefruit juice was too small to significantly affect BP or HR. The clinical significance of this food/drug interaction, however, cannot be ignored since there is considerable variation between individuals and a more extensive intake of grapefruit juice might give more pronounced effects.

Administration, Oral↗
PubMed1995

Taking antihypertensive medication--controlling or co-operating with patients?

Low compliance with antihypertensive drug regimens has been a well documented reason for inadequate control of hypertension. We assessed recent literature regarding compliance from different disciplines to clarify the nature of reported problems on low compliance to prescribed antihypertensive medication. Much research focuses on primary factors for compliance, methods to monitor and measure individual rates and patterns of compliance. From a behavioural oriented point of view, the focus is on understanding why patients act as they do. This review indicates that there is an almost complete lack of knowledge about how the decision making in the clinical practice is organized when prescribing antihypertensive medication and/or when following up treatment from patients already taking such drugs. Since the concrete communication and collaboration between patient and physician in the clinical setting are of prime significance for patient adherence to drug regimens, it is important to shed light on what happens in this critical situation.

Antihypertensive Agents↗
PubMed1995

Cold exposure increases cyclic guanosine monophosphate in healthy women but not in women with Raynaud's phenomenon.

OBJECTIVE: To investigate influence of whole-body cooling on cyclic GMP (cGMP) in women with Raynaud's phenomenon and in healthy women. DESIGN: The study was performed as an open, parallel-group comparison between women with Raynaud's phenomenon and healthy women during the winter month of February. SETTING: The municipality of Västerås (Sweden). PARTICIPANTS: The Raynaud group comprised 24 female patients. The control group consisted of 21 healthy females. MAIN OUTCOME MEASURE: The venous levels of cGMP were measured on three different occasions: just before and after 40 min of whole-body cooling and after 20 min rest at room temperature (21 degrees C). RESULTS: Venous cGMP increased significantly in the control group after cold exposure (mean difference 0.43 pmol mL-1; 95% CI, 0.018-0.848; t = 2.18; df = 20; P = 0.02) and remained at a high level after 20 min rest (mean difference 0.58 pmol mL-1; 95% CI, 0.063-1.108; t = 2.34; df = 20; P = 0.015). In contrast, the levels of venous cGMP in the Raynaud group did not change significantly. The difference in increase between the two groups was significant (P < 0.02). The diastolic blood pressure in the Raynaud group increased after 40 min of whole-body cooling and was still significantly increased (P < 0.001) after 20 min rest at room temperature (21 degrees C). CONCLUSION: These results indicate that women suffering from Raynaud's phenomenon lack the physiological response of cGMP to cold exposure, which may explain their increased vasospastic response.

Adult↗
PubMed1995

Tolerance development and arterial and venous tissue-/plasma levels of glyceryl trinitrate and glyceryl dinitrate in patients treated with nitroglycerin infusion.

Venous vessels (vena saphena magna) and arteries (left internal mammary artery) from patients treated with long-term ( > 24 h) intravenous infusions of nitroglycerin (CAS 55-63-0, glyceryl trinitrate, GTN) prior to coronary by-pass surgery were studied. Tissue concentrations of GTN and its dinitrate metabolites were determined as well as plasma-concentrations of GTN and glyceryl dinitrates (GDN's) on both the arterial and the venous side. The relaxant effect of GTN on the isolated vein preparations was studied and compared with those from two other groups of patients, one not exposed to GTN and the other exposed to a short-term infusion of GTN. Wide variations were found both in plasma and in tissue concentrations of GTN and GDN's on the venous and the arterial side. However, no extraction across the arterial-venous bed could be observed. Correlations were found between the dose given and the concentrations of drug and metabolites in both venous and arterial plasma as well as between 1,2-GDN in venous plasma and venous tissue, between 1,2-GDN in arterial plasma and arterial tissue and the same applied to 1,3-GDN on the arterial side. No correlations were found between the tissue concentrations of drug or metabolites and the relaxation induced by GTN in vitro. Venous vessels from patients treated with long-term infusions of GTN showed a pronounced decrease in relaxation as compared to vessels from patients not treated with nitroglycerin infusions and a slight decrease as compared to veins from patients treated with a shortterm infusion.

Aged↗
PubMed1995

Inhibition of nisoldipine on bovine mesenteric arteries and veins and on human peripheral veins.

The inhibiting effect of the calcium channel blocker nisoldipine (CAS 63675-72-9, Baymycard, Syscor) on potassium-induced contraction on bovine mesenteric veins and arteries and human peripheral veins was investigated. Nisoldipine inhibited the contraction on bovine mesenteric veins at a significantly lower concentration (1 x 10(-10) mol/l) than nifedipine and glyceryl trinitrate (GTN) (1 x 10(-7) mol/l). When the preparations were preincubated with the drugs, nisoldipine reduced the contraction, measured as area under the curve (AUC), with 47 +/- 8% (mean +/- SEM) and nifedipine with 29 +/- 13% in veins. It was necessary to use an inconsiderably higher concentration of nisoldipine to relax bovine mesenteric arteries contracted by potassium. Preincubation of these arteries with nisoldipine (1 x 10(-7) mol/l) reduced contraction measured as AUC by 46 +/- 10% and preincubation with nifedipine (1 x 10(-7) mol/l) by 77 +/- 3%. Nisoldipine also caused a marked relaxation in human saphenous veins. The introduction of nisoldipine (1 x 10(-8) mol/l) after potassium-induced contraction caused 54 +/- 8% relaxation.

Animals↗