cough syrup and alcohol

hey everyone! kind of stressing here

i took cough syrup, contains dextromethorphan and guaifenesin, those are the only active ingredients. the recommended dose is 20ml every 4 hours. I took 20ml at 1pm and then another 20ml at 5:30. planning on going out with friends tonight, how long should i wait to consume any alcohol?

thanks for any help