The side effects that you describe are part of a neuro/psychological reaction called depersonalization. Family members of certain antibiotic types can have bizarre interaction with nerve cells. Tetracycline drugs are a big family and though it is important to list any previous reactions such as itching or any change in activity or mood to any antibiotic, so many variants exist, you may not even know they're in the tetracycline family. This story is a good reminder to watch for all sorts of reactions.
One of minocycline's qualities, like doxycycline, and most tetracycline drugs is the ability to get past the blood - brain barrier. Its unique structure allows minocycline to pass through lipids that make up the blood - brain barrier and as such can and does interact with the brain.
First, this is far from all bad. Bacterial meningitis and any number of brain infections are cured because of this quality. Minocycline is effective in treating symptoms of Parkinson's disease and other brain conditions. Anything having such wide ranging positive effects has the potential for undesirable effects needs to have clear warnings. It is an excellent antibiotic for reaching into tissues that other antibiotics may not.
The idea of an induced depersonalization is potentially disturbing. Images of a Manchurian candidate come to mind. Fortunately in the case of minocycline, stopping it will reverse the effects. If your child is traumatized by having his reality forced into a bad place, some counseling might be in order. Depending on how long this went on and how severe the effects, consider an evaluation with a Psychiatrist. I don’t mean to jump to Psychiatrists over Psychologists, both are equally important. Mood stabilizing medications such as anti-depressants should be managed by a Psychiatrist if there is an overriding medical condition like CF.
A case in point, lithium salts are used to treat Bipolar disorder in certain cases. The amount of electrolyte introduced by lithium salts can be near the toxic limit. This situation would be potentially dangerous in a person with CF. Drug interactions that affect the brain or the mind may be caught sooner with a psychological professional in the loop.
Depression, its manifestations, anger, mood swings and inappropriate emotions or emotional intensity are part of depersonalization, detachment to depression and loss of executive mental function. Executive mental function is our self-monitoring to behave in a socially appropriate manner.
The term is fairly self-defining because it is a disassembly of the personality of sorts. Varying degrees are from mild dissociation from yourself and others to near total dissociation from everyone and everything while retaining a third person vantage of yourself. This is a rare side effect but I wish doctors and patients could rationally discuss side effects and rate of occurrence. Not every doctor and not all patients react to a statistical probability in an appropriate manner. Doctors rarely volunteer information because the less said, the less to misunderstand.
Depression is not for amateurs. I cannot emphasize this enough, a combination of counseling and mood stabilizing / antidepressant drug therapy always works, with the rare exception. Going with counseling alone may be adequate but drug therapy alone is asking for a protracted journey toward good mental health.
I feel bad that this serious and probably a little incredible reaction to an antibiotic had to affect your son, and his family. This is a rare but important to recognize reaction to antibiotics and of course the entire family of mood stabilizing drugs used to treat mental illnesses.
If I can offer a caution. As long as there might be a return to the primary effect, depression, try to make certain that access to medication is monitored at a minimum and controlled if there is any chance of suicidal ideation or thoughts of doing harm to himself. By having a psychological professional help his return to good mental health, he/she can provide professional eyes watching for signs of danger.
Best luck in a full recovery,
LL
