Dear Dr. Roach >> I received the pneumonia vaccination (Pneumovax 23) two weeks ago, and I was OK immediately afterward, apart from having a sore arm for a day. But I have felt extremely tired in the past couple of days. Could this be a delayed reaction to the vaccine?

I am due to have the second Shingrix vaccination tomorrow, but I’m wondering whether it might be better to leave it until I am feeling less exhausted. What do you think? After the first Shingrix vaccination, I felt shivery and exhausted for three days.

— L.D.

dear reader >> I don’t think it was a reaction to the pneumonia vaccine after two weeks. The polysaccharides that comprise the vaccine are long gone at this point. Apart from live vaccines, delayed reactions to vaccines (more than 48 hours) are extremely rare.

In many parts of the country, COVID is very prominent right now, and this is the first thing I worry about when I see a person who is feeling very tired. But of course, there are many other causes. It is probably worth a visit to your doctor if you aren’t getting better.

As far as the shingles vaccine goes, I don’t recommend getting the vaccine if you are under the weather. Many people will get a reaction to the shingles vaccine that rarely lasts more than a day or two. Sometimes people who had a bad reaction to the first don’t get a bad reaction to the second, but it’s still wise to prepare. I wouldn’t get the vaccine a day before you have something critically important to do, just in case you do have a reaction.

Finally, I still strongly recommend the vaccine because the threat from shingles can be very great. In the best cases, people are in moderate pain for a week or so. However, shingles can cause serious complications, including serious eye and brain disease, even strokes.

Dear Dr. Roach >> My pharmacy was affected by a recent computer outage, and for a few days, I was unable to fill my lamotrigine prescription, which I take for seizures. After about 36 hours off of the medicine, I felt woozy and numb with a headache. Was this caused by not being on lamotrigine?

— M.B.W.

dear reader >> Lamotrigine is usually prescribed for seizures, but it is also indicated for bipolar disorder. It is sometimes used for depression, to prevent migraines, or as a treatment for trigeminal neuralgia. Stopping seizure medicines can lead to seizures, which is one reason why it’s so important to take these medications regularly. But there are reports of withdrawal symptoms to lamotrigine when it is stopped suddenly.

The reported symptoms include tremors, sweating, and a fast heart rate. Other reports include headache, fatigue, and feeling “unfocused.” Physical symptoms (“body tingles”) have also been reported. These symptoms can occur no matter what lamotrigine is prescribed for.

Lamotrigine is not well-known to cause withdrawal symptoms, but it’s possible that your symptoms might be due to withdrawal. Restarting your medication as quickly as possible would be likely to improve these symptoms. Pharmacists often give a few tablets to prevent withdrawal.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.