Ferrara 1984.

Methods	Single‐centre study Randomization: "...patient were randomly given a single dose of placebo, captopril 50 mg, methyldopa 500 mg, or indapamide 2.5 mg." Blinding: not reported Withdrawals: none Lost to follow‐up: none Treatment duration: single dose study Analysis type: unclear
Participants	Geographic region: Naples, Italy Study setting: outpatient clinic N=24 Age range: 26‐60 Gender: 18 males, 6 females Race: not reported Blood pressure at entry: Mean supine blood pressure ‐ Methyldopa arm (127.7), Placebo arm (125.2), Captopril arm (128.0), Indapamide arm (120.8) Co‐morbid conditions: not reported Inclusion criteria: essential hypertension Exclusion criteria: target organ damage secondary to hypertension
Interventions	All anti‐hypertensives and any other drugs were discontinued for a two week washout period before trial entry Methyldopa 500 mg x one dose (N=6) Placebo x one dose (N=6) Captopril 50 mg x one dose (N=6) Indapamide 2.5 mg x one dose (N=6)
Outcomes	Supine blood pressure Supine heart rate Arterial blood flow
Notes	Single dose study (blood pressure was measured every 30 minutes for 5 hour after the dose was given). Reported data comparing methyldopa and placebo on reduction in blood pressure 30 minutes and four hours after single dose given; thus, no real useable data from this study. Assessment of medication compliance: not reported Final number of patients included in each arm when reporting results: Methyldopa arm (6); Placebo arm (6); Captopril arm (6); Indapamide arm (6)
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Unclear
Allocation concealment?	Unclear risk	Unclear
Blinding? All outcomes	High risk	Open label
Incomplete outcome data addressed? All outcomes	Low risk	All randomized patients accounted for at end of study
Free of selective reporting?	Low risk	Reported on all pre‐specified outcomes of interest