CHRM2 and asthma: Agents that block the M2 muscarinic receptor and the D2 dopaminergic receptor are associated with an increased risk of severe asthma exacerbation (adjusted OR: 1.39, 95% CI 1.10–1.76, P = 0.007 and adjusted OR: 1.33, 95% CI 1.08–1.63, P = 0.008, respectively).