Irebel is on the right track.

One of the ingredients in Actifed was Pseudoephedrine [1], and due to regularly increasing rates of abuse, and large purchases used to manufacture illicit substances, its status was changed, and to gain better control of the supply, it was moved behind the pharmacy counter, so someone could only purchase a certain amount, plus they had to sign for it, and show identification when buying it.

Once this happened, it severely cut down on sales, and some manufacturers discontinued their products due to it no longer being financially feasible to continue manufacturing it.

The FDA lists its typical side effects as possibly including nausea, dizziness, nervousness, irritability, and insomnia.

Ref: Pseudoephedrine Information

The new formulation [NDC 27854-119] contains Chlopheniramine and Phenylephrine (or Phenylephrine by itself), to avoid the law that requires products containing Pseudoephedrine to be kept behind the counter and sold in limited quantities. [2], [3]

Hope this helps!