- Hypertensive urgencies are defined as severe elevations in blood pressure (diastolic blood pressure above 120 mmHg) without evidence of acute, progressive target organ damage.
- The target organs are primarily the heart, brain, kidneys and large arteries
- Initial treatment should aim for about 25% reduction in BP over 24-48 hours but not lower than 160/90 mmHg.
- A short period (30+ min) of rest in a quiet, dark room often is effective in lowering BP 15-20% & is usually recommended for initial management
- If the initial managment is ineffective, oral drugs proven to be effective and there is no role for intravenous BP lowering drugs.
Oral Drugs for Hypertensive Urgencies: Systematic Review and Meta-Analysis
Drug | Captopril | Nifedipine |
Outcome | ||
Total mortality | No trial reported total mortality | |
Adverse effects | Flushing : (risk ratio 0.22; 95% confidence interval 0.07 to 0.72) Headache (risk ratio 0.34; 95% confidence interval 0.13 to 0.92) (Captopril < Nifedipine) | |
Proportion of patients with blood pressure decrease | Only one study described this outcome as part of the results, and it showed that the proportion of blood pressure decrease over four hours was 92% for both groups (captopril and nifedipine) | |
Proportion of patients with target blood pressure of 140/90 mmHg | No trial reported this outcome | |
Number of patients requiring addition of a second or third drug | _ | Four trials reported the outcome of 2 patients in the CCB group required additional drug |
Total non-fatal cerebrovascular, cardiovascular and cardiopulmonary events | _ | One trial reported one patient with angina after taking CCB to treat hypertensive urgency |
Time taken to achieve target blood pressure | Ranged from 30 minutes to 120 minutes | Ranged from 30 minutes to 100 minutes |
Treatment of Hypertensive Urgencies with Oral Nifedipine, Nicardipine, and Captopril
(The Journal of Vascular Disease, SAGE publication)
- Nifedipine - BP and HR were assessed for 6 hours after intake of the antihypertensive agents. Within 60 minutes, nifedipine reduced blood pressure by an average of 74.7 mmHg for the systolic and 35.4 mmHg for the diastolic. Average heart rate increased significantly by 11.6 beats/min at within 30 minutes
- Nicardipine and captopril - Produced equivalent falls in systolic (-81.6 and -79.4 mmHg) and diastolic (-37.3 and -33 mmHg) BP respectively, but did not increase HR significantly.
- The authors conclude that nifedipine, nicardipine, and captopril show similar efficacy in the treatment of hypertensive urgencies despite of HR elevation effect.
Hypertensive Urgency Management - cited from the recent report of the JNC VI (Nov, 1997)
- Concerns regarding short acting nifedipine have arisen due to association with increased AMI, CVA & mortality.
- Revised labeling for short acting nifedipine in the USA recommends against its use in hypertensive crisis.
- The recent report of the JNC VI (Nov, 1997) also cautioned against the use of nifedipine in hypertensive crisis.
- In practice, this concern may be greater in older individuals and those at higher risk of cardiovascular/cerebrovascular disease.
- As always, the risk verses benefit ratio must be considered.
- Captopril have been suggested as better oral alternatives to nifedipine based on the current understanding of their cardiovascular & cerebral effects.
Conclusion
- Evidence currently exists to suggest that the use of oral ACEi drugs for hypertensive urgencies produces better outcomes with regard to effectiveness and lower frequency of adverse effects, compared with CCB drugs.
- Thus, when possible, oral ACEi drugs should be used, except during pregnancy
- However, nifedipine can always be another alternative if captopril is unavailable, contraindicated or untolerated
References
- Clinical Practice Guidelines: Management of Hypertension 4th Edition
- Oral drugs for hypertensive urgencies: systematic review and meta-analysis. http://www.scielo.br/pdf/spmj/v127n6/09.pdf
- Treatment of hypertensive urgencies with oral nifedipine, nicardipine, and captopril. https://www.ncbi.nlm.nih.gov/pubmed/2042792
- Alternatives to Nifedipine in the Oral Treatment of Hypertensive Urgencies (HU). http://www.rxfiles.ca/rxfiles/uploads/documents/nifed-hu.pdf
Post a Comment