Third-party tests found over 70 vials of the antivenom for soldiers would be needed to treat bites from some snakes

The US army spent nearly $1m (£750,000) last year on anti-snake venom drugs for troops, which evidence suggests may have weak efficacy.

The two drugs do not appear to have undergone any independent testing for safety or effectiveness, an investigation has found, despite evidence that the civilian version of one of the drugs tested had weak efficacy.