Grapefruit juice risky for patients with long QT syndrome: research

By Admin -
Grapefruit juice risky for patients with long QT syndrome
Grapefruit juice prolongs the QT interval and may impose risks for patients with congenital long QT syndrome, recent research carried out by leading medical investigators suggests.

The research was published in HeartRhythm, the official journal of the Heart Rhythm Society and the Cardiac Electrophysiology Society.

The QT interval is the time it takes the heart muscle to recharge between beats. Over 200 commonly used medications prolong the QT interval including not only antiarrhythmic drugs, but medications with no cardiac indications such as some antibiotics, antihistamines, and antipsychotic drugs.

Investigators have now confirmed the QT-prolonging effects of grapefruit juice and call for a stronger warning to patients taking such drugs.

"With so many drugs, of such varied composition blocking the IKr channel, it is reasonable to assume that food compounds may also have IKr-channel-blocker properties, raising the possibility that 'proarrhythmic food' exists," said Dr Sami Viskin, MD, Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel, who led the study.

The drugs work by blocking a specific "IKr" potassium channel on the cardiac muscle cell membrane and prolonging the repolarization in the heart ventricles.

"Previous studies showed that flavonoid compounds contained in grapefruit juice have IKr channel- blocking properties. We therefore tested the possibility that grapefruit juice has QT-prolonging properties," said said Dr Sami Viskin.

Thirty healthy volunteers and ten patients with congenital long QT syndrome took part in the study, which confirmed that grapefruit juice prolongs the QT interval.

Dr Viskin and his colleagues conclude that stronger warnings should be given against drinking grapefruit juice in large quantities for patients taking cardiac or non-cardiac medications that prolong the QT interval.

The study does not imply that daily consumption of grapefruit juice is risky for the general population, and grapefruit juice is low in calories, high in nutrients, promotes appetite controls and has been shown to aid weight loss.

"The net increase in QT interval caused by grapefruit among healthy volunteers was small, but in the range that, if grapefruit juice were a new drug in development, the results of the present study would probably lead the FDA to call for additional studies before issuing a final recommendation based on its expected benefits and risks," commented Dr Viskin.



from Health - SUCH TV http://bit.ly/2FUOlyv

Comments

Post a Comment

Popular posts from this blog

At least 11 dead, others injured after train catches fire near Rahim Yar Khan

By Admin -
Image
At least 11 passengers lost their lives and 30 others sustained burn injuries when three carriages of a Tezgam Express caught fire due to explosion in a gas stove, according to initial reports. Meanwhile, firefighters have initiated a rescue operation to extinguish the fire and other passengers are being evacuated from the train to safe places. The affected carriages are being separated from the train. The train, Tezgam, was on its way from Karachi to Rawalpindi, when a gas cylinder carried by a passenger exploded, leaving several dead and injured. The fire was caused by the explosion in a gas cylinder, confirmed the Pakistan Railways official. According to details, the passengers were cooking breakfast when the gas cylinder exploded. After the blast, the raging fire engulfed two other coaches as well. Fire fighters were still extinguishing the fire as per last reports.
Read more

Three soldiers martyred in terrorist attack on checkpost in Balochistan’s Zarghoon

By -
Image
As many as three soldiers embraced martyrdom and one terrorist was killed in an exchange of fire between security forces and terrorists in Zarghun, the area of Balochistan on Saturday. According to the military’s media wing, the Inter-Services Public Relations (ISPR), an operation was launched in the area against suspected terrorists who attacked a security post. “Troops on the post retaliated readily to the fire raid thereby, pushing back the terrorists,” stated the military’s media wing. In the ensuing exchange of fire, three soldiers were martyred while one terrorist was also killed. The military identified the martyred soldiers as Sepoy Zaheer Ahmed, Sepoy Mudassir Shaheed and Lance Naik Abdul Qadeer. The ISPR stated that the post had recently been established to “check extortion efforts targeting coal mines in the area”. “Based on follow-up ISR effort, likely hideout of fleeing terrorists has been identified in nearby mountains and a deliberate blocking and sanitisation op...
Read more

Legal process to try May 9 planners, perpetrators under army act begins: COAS

By -
Image
Chief of Army Staff (COAS) General Asim Munir has said that the legal process of trial against planners, instigators, abettors and perpetrators involved in the May 9 mayhem has commenced under Pakistan Army Act and Official Secret Act as per existing and established legal procedures derived from the Constitution. The army chief's statement came as he visited Jinnah House and an army installation in Lahore, which were blatantly attacked and vandalised by “politically motivated” rioters, the Inter-Services Public Relations (ISPR) said in a handout. The COAS was also given a briefing on events of May 9 dubbed by the military as ‘Black Day’ — the day when Pakistan Tehreek-e-Insaf (PTI) supporters ransacked and torched military installations across the country following the arrest of their leader Imran Khan in a graft case. Addressing the garrison officers and soldiers at Corps Headquarters, Gen Munir emphasised that any action aimed at widening a gulf between people and the milita...
Read more