Welcome to the daily Halacha (Jewish law). If a person needs to drink a few cups of water or other drinks in order to take his pills, is he allowed to do that before Shacharit (morning prayer), yes or no? We know Maran HaShulchan Aruch writes: A person is not allowed to eat or drink before Shacharit, based on the Gemara and Berachot. A person should first take care of his ruchniyut, tefillah. A person should first nourish and take care of his spirituality, which is praying, before he takes care of his bodily needs, his guf, which is eating and drinking. It is based on the Gemara and Berachot. Therefore, halacha lema'aseh (in practice), a person should not eat or drink before Shacharit.
However, halacha lema'aseh says that you're allowed to drink in order to take down the pill. Even if a person needs a sweet drink, he's allowed to have it if it will help him take down the pill. Water, no matter what, is allowed before Shacharit. If a person is thirsty for water when he wakes up, before he goes to pray, he's allowed to have water. But sweet drinks like orange juice, Gatorade, and apple juice are not allowed before Shacharit. The reason coffee is allowed before Shacharit is really based on a long teshuvah (responsum) from the Chida in the Ginat Veradim, and Chacham Ovadia has a long arichut (lengthy discussion) about it. How are we allowed to drink coffee before Shacharit? The Heter (permission) started because we compare coffee to water, but only without sugar. Then the Chachamim (Sages) said that in our generation, it's very hard to have coffee without sugar. So you can't just tell people to have coffee without sugar, because then it's as if they're not going to have the coffee. Therefore, we have to have sugar with the coffee. Fine. Coffee with sugar before Shacharit is allowed. Then the Chachamim said that people can't have coffee with sugar but without milk. Therefore, they added milk before Shacharit too.
Even though I saw many rabbis in my yeshiva having coffee before Shacharit, they did not have it with milk. They were very machmir (stringent) about not putting milk in their coffee before they prayed Shacharit. But halacha lema'aseh, if one needs milk and sugar in his coffee, of course he can have regular coffee before Shacharit. That's a minhag, that's a tradition. But all the other drinks, like I said before—orange juice, Gatorade, apple juice, cherry—what is it?—cranberry juice—all those drinks, the poskim (halachic authorities) said a person is not allowed to drink before Shacharit, and one has to be careful. However, if a person needs one of those drinks to help him take down his pills because he can't use water or doesn't have access to water, he's allowed to have those drinks before Shacharit in order to take down his pills, and he should make a Beracha (blessing) on those sweet drinks. At the end of the day, he's not going to have those drinks before Shacharit. It tastes good. More than that, let's say it's an old man who needs to eat something before he takes his medicine before Shacharit. He's also allowed to eat before Shacharit to help him take his medicine, so he shouldn't take it on an empty stomach. As for the food, don't have too much in order to take your medicine. A person has to be very careful to eat only what he needs in order to take his medicine. Otherwise, a person is not allowed to eat or drink before Shacharit.