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Effect of guancydine on systemic and renal hemodynamics in arterial hypertension
Insights
Guancydine (1-cyano-3-tert-amylguanidine) lowered blood pressure in hypertensive patients but did not normalize it in most. The drug also caused adverse effects and did not show an anti-angiotensin effect in humans.
Area of Science:
- Pharmacology
- Nephrology
- Cardiology
Background:
- Arterial hypertension is a significant global health concern.
- Understanding the hemodynamic effects of novel antihypertensive agents is crucial for treatment optimization.
Purpose of the Study:
- To investigate the effects of guancydine on systemic and renal hemodynamics in patients with arterial hypertension.
- To evaluate the efficacy and safety profile of guancydine in a human clinical setting.
Main Methods:
- Nine patients with arterial hypertension participated in the study.
- Patients received a placebo followed by guancydine (average dose 21 mg/kg) for 7–18 days.
- Systemic and renal hemodynamic parameters, including blood pressure, cardiac output, glomerular filtration rate, and renal plasma flow, were monitored.
Main Results:
- Guancydine significantly decreased mean arterial blood pressure in all patients, but only two achieved normal levels.
- No significant changes were observed in cardiac output, glomerular filtration rate, or renal plasma flow.
- Urinary sodium excretion decreased, suggesting potential activation of the renin-angiotensin-aldosterone system. Adverse effects were common.
Conclusions:
- Guancydine demonstrates antihypertensive properties but has limited efficacy in normalizing blood pressure in this patient cohort.
- The drug's effects on renal hemodynamics and potential activation of the renin-angiotensin-aldosterone system warrant further investigation.
- Observed adverse effects may limit the clinical utility of guancydine.
Abstract:
The effect of guancydine (1-cyano-3-tert-amylguanidine) on systemic and renal hemodynamics was studied in nine patients with arterial hypertension. Antihypertensive drugs were withheld for 15 days before beginning the investigation. Average sodium intake was 105 meq/24 hours in some patients and 25 meq/24 hours in others. Patients received placebo during a control period that averaged 14 days. Guancydine was given for 7 to 18 days at an average dose of 21 mg/kg of body weight. Although mean arterial blood pressure decreased significantly in all patients, it reached normal levels in only two. There was no change in cardiac output. Glomerular filtration rate and renal plasma flow remained unchanged, whereas urinary sodium excretion diminished, suggesting an activation of the renin-angiotensin-aldosterone system. A substantial gain in body weight was noted. Nausea, vomiting, constipation, somnolence, restlessness, mental confusion, asthenia, and urine retention were observed. The anti-angiotensin effect of guancydine that has been described in animals was not observed.