Astemizole
Astemizole (marketed under the brand name Hismanal, developmental code R43512) was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It has been withdrawn from the market in most countries because of rare but potentially fatal side effects (QTc interval prolongation and related arrhythmias due to hERG channel blockade).
Tubocurarine chloride
Tubocurarine has a time of onset of around 5 minutes which is relatively slow among neuromuscular-blocking drugs, and has a duration of action of 60 to 120 minutes. It also causes histamine release, now a recognized hallmark of the tetrahydroisioquinolinium class of neuromuscular blocking agents. Histamine release is associated with bronchospasms, hypotension, salivary secretions, making it dangerous for asthmatics, children, and those who are pregnant or lactating. However, the main disadvantage in the use of tubocurarine is its significant ganglion-blocking effect, that manifests as hypotension, in many patients; this constitutes a relative contraindication to its use in patients with myocardial ischaemia.