Impact of interaction between calcium antagonists and grape fruit juice on blood pressure in clinical settings

Impact of interaction between calcium antagonists and grape fruit juice on blood pressure in clinical settings - Impact of drug-food interactions in clinical settings

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000006303

Enrollment

Registered

2011-09-07

Start date

2011-09-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

hypertension

Interventions

grapefruit juice water

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Hypertensive patients treated with amlodipine or nifedipine 1) Systolic blood pressures of morning and evening are not over 200 mmHg at home in observation period. 2) Changing antihypertensive drugs was not carried out at past one month.

Exclusion criteria

Exclusion criteria: 1) Patients with severe hepatic dysfunction. 2) Patients take drugs what are not allowed with grapefruit juice. 3) Patients who were judged inappropriate by doctor.

Design outcomes

Primary

Measure	Time frame
Home blood pressure and trough drug concentration	—

Secondary

Measure	Time frame
frequency of side effects	—

Countries

Japan

Contacts

Public ContactUchida Shinya

School of Pharmaceutical Sciences, University of Shizuoka Department of Pharmacy Practice and Science

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026