Key Takeaways
- Quinolone antibiotics, the class that includes ciprofloxacin (Cipro), levofloxacin (Levaquin), moxifloxacin (Avelox), and ofloxacin, can set off acute benzodiazepine withdrawal in a person on a steady dose, in a taper, or recently off the drug.
- Professor C. Heather Ashton wrote that quinolones displace benzodiazepines from their binding sites and should not be taken by patients on, or recently on, benzodiazepines.
- The ciprofloxacin label never mentions benzodiazepines, so the prescriber in front of you has probably never seen the warning and needs to hear it from you.
- The reaction feels like a sudden dose cut, because the antibiotic has taken the benzodiazepine’s place at its receptor, even though the tablet is still being taken on schedule.
- Before accepting the prescription, tell the prescriber that you take or recently took a benzodiazepine and ask whether another antibiotic would treat the infection. Often, one would.
- If symptoms have already started, do not stop the antibiotic or raise the benzodiazepine on your own. Call the doctor who wrote the antibiotic the same day, since the usual answer is a switch to a different class of antibiotic.
- A seizure, confusion, hallucination, or any thought of harming yourself is an emergency: call 911 or your local emergency number, and in the United States call or text 988.
- Many people settle within days of the last antibiotic dose, and others describe a longer wave. Professor Ashton’s warning gives no number, and this site does not guess at one.
Can an antibiotic bring on benzodiazepine withdrawal?
Yes, one class of antibiotics can. Quinolone antibiotics, the group that includes ciprofloxacin (Cipro), can set off acute withdrawal in a person who takes a benzodiazepine at a steady dose, who is tapering, or who stopped recently.
This is not a rumor from a patient forum. Professor C. Heather Ashton addressed it directly in her 2011 Supplement to the Ashton Manual, in the section on recurrence of symptoms after successful withdrawal. There she singled out quinolone antibiotics as an exception among medicines: they displace benzodiazepines from their binding sites, and they should not be taken by patients on, or recently on, benzodiazepines.
That one sentence is the reason this article exists. What does it mean for you, and what should you do with a prescription for Cipro in your hand?
Which antibiotics are quinolones?
The class is usually called the fluoroquinolones. Ciprofloxacin, sold as Cipro, is the best known, and the group also includes levofloxacin (Levaquin), moxifloxacin (Avelox), and ofloxacin. They are prescribed for urinary tract infections, chest and sinus infections, some skin and bowel infections, and a few conditions where nothing else works.
The ciprofloxacin prescribing information carries a boxed warning of its own. It says the drug has been associated with disabling and potentially irreversible reactions, including tendinitis and tendon rupture, peripheral neuropathy, and central nervous system effects, and it tells prescribers to reserve ciprofloxacin for patients with no alternative when the diagnosis is an uncomplicated bladder infection, acute sinusitis, or a flare of chronic bronchitis.
What the label does not do is mention benzodiazepines. It runs to many pages, lists anxiety, agitation, insomnia, and nightmares among the drug’s own possible effects, warns that the drug can lower the seizure threshold, and never once says the word benzodiazepine. So, the warning that matters most to a reader of this site lives in a supplement to a manual, not in the paperwork stapled to the pharmacy bag.
What does a quinolone do at the GABA-A receptor?
Chapter I of the Ashton Manual explains how benzodiazepines work. Gamma-aminobutyric acid, or GABA, is the brain’s natural quieting neurotransmitter, and benzodiazepines act at their own special sites on the GABA receptor, where the Manual describes them as a booster to GABA. The receptor type involved is now usually called the GABA-A receptor, and that is the name used below.
With continued use, the Manual says, those receptors become less responsive, which is tolerance, and by then the brain is relying on the drug to hold an ordinary level of calm. A quinolone displaces the benzodiazepine from that site. The benzodiazepine is still in the blood, and the tablet is still being swallowed on schedule, but at the receptor it has lost its seat.
The 2020 Food and Drug Administration (United States Food and Drug Administration (FDA)) label update for all benzodiazepines warns that abrupt discontinuation or rapid dose reduction after continued use may precipitate acute withdrawal reactions, which can be life-threatening. The update is about doses, not receptors. Yet, in this site’s reading of the Supplement, a quinolone produces the same kind of loss at the receptor without anyone reducing anything.
Why does it feel like a sudden dose cut?
Imagine a passenger who has held the same seat on the same morning train for years, and a trip arranged around that seat: the coffee is delivered there, the newspaper is left there, and the conductor stopped asking for a ticket long ago.
One morning a stranger sits down in it first, and the regular is left standing in the aisle with a valid ticket. The seat is taken, and nothing about the trip works the way it worked yesterday. The quinolone is the stranger, the benzodiazepine is the passenger in the aisle, and the withdrawal is the trip that no longer works.
Arguing in the aisle does not fix it. The stranger has to leave the seat, and that is a decision for the prescriber, not for the reader alone.
Who is at risk?
Anyone whose GABA-A receptors have adapted to a benzodiazepine. That includes a person on a stable prescribed dose, even a low one, because adaptation happens at any dose taken long enough. It includes a person in the middle of a taper, whose receptors are already being asked to adjust and have the least room to spare. And, it includes a person who finished a taper not long ago, which is why Professor Ashton wrote “or recently on.”
It may also include people well past a taper. The Supplement’s warning sits in a section about symptoms that return after a successful withdrawal, and in this site’s reading that is no accident: readers in protracted withdrawal often describe a quinolone as the thing that brought a wave back.
Ashton Manual Guide applies the same caution to the z-drugs, zolpidem (Ambien), zopiclone, and eszopiclone (Lunesta), in its own voice rather than Professor Ashton’s. They act at the same receptor and are tapered on the same principles.
What does quinolone-triggered withdrawal look like?
Like acute benzodiazepine withdrawal, because that is what it is. Patients often describe it starting within the first day or two of the antibiotic, sometimes after a single dose: a steep rise in anxiety, insomnia, inner restlessness, muscle tension, tremor, a racing heart, sensitivity to sound and light, and the unnerving sense that the usual dose has stopped working. The full range is covered in this site’s guide to benzodiazepine withdrawal symptoms.
Unfortunately, the timing invites the wrong conclusion. Patients have described being sent home from an emergency department with a diagnosis of panic disorder, or being asked whether they had taken more than prescribed, when the only thing that changed that week was a new antibiotic for a bladder infection. A person whose dose has not moved and whose nervous system is in withdrawal has a physical dependence, and dependence is not addiction.
What should you do before accepting the prescription?
Tell the prescriber, before the script is written, that you take a benzodiazepine or came off one recently. Say the words “quinolone” and “Ashton Manual Supplement” if you need to, because the interaction is not on the label and many doctors have never heard of it. Then ask whether another antibiotic would treat the infection.
Often it would. The ciprofloxacin label itself tells prescribers to keep the drug for patients with no alternative when the problem is an uncomplicated bladder infection, sinusitis, or a bronchitis flare, and those are the everyday infections behind most quinolone prescriptions. Asking for a non-quinolone is asking the prescriber to follow the label, and a pharmacist can raise the same question if the doctor has already left the room.
Of course, there are infections for which a quinolone is the right drug, or the only one. Then the conversation turns to planning: the taper doctor is told, the taper is held for the duration, and you know which symptoms to expect and whom to call. None of this is carelessness on the prescriber’s part. The paperwork never gave them the warning.
What if you are already taking it and the symptoms have started?
Do not stop the antibiotic on your own, and do not raise the benzodiazepine on your own. Stopping leaves an infection half treated, and raising the dose blind is a change to a taper that nobody planned. Both decisions belong to the prescriber, and both can be made the same day by phone.
Call the doctor who wrote the antibiotic and say plainly what is happening: benzodiazepine, quinolone, withdrawal symptoms since the first doses. The usual answer is a switch to a different class of antibiotic. If a taper is under way, call the taper doctor as well.
Fortunately, a hold is the ordinary response to any outside disturbance in a taper, and Chapter II of the Manual says that a reader who reaches a difficult point can stop there for a few weeks if necessary. When the course is over, the taper resumes from the dose being held, at the pace that was working before. The benzodiazepine taper calculator on this site can lay that shape out again, as a planning tool for a conversation with your prescriber.
When is it an emergency?
A seizure is an emergency. So is confusion, hallucination, or any thought of harming yourself, all of which appear on the ciprofloxacin label as possible reactions in their own right and are also known features of severe benzodiazepine withdrawal. Call 911, or your local emergency number, for a seizure or any medical emergency, and in the United States call or text 988, the Suicide and Crisis Lifeline, for thoughts of suicide.
Emergency staff may not know the interaction either. Bring the pill bottles, say the word withdrawal, and say when the antibiotic started. Never let the fear of being disbelieved keep you out of the emergency department.
How long does it last once the antibiotic stops?
This is the question everyone asks, and the honest answer is that the Supplement does not give a number, so this site will not invent one. In clinical experience, which varies, many people settle within days of the last dose, while others, especially those already in a taper or in protracted withdrawal, describe a longer wave that fades in the pattern described in this site’s article on windows and waves.
Yet the direction is reliable even when the pace is not. The benzodiazepine returns to its site when the quinolone leaves, and a nervous system that adjusted once can be expected to adjust again. The wave passes.
The Ashton Manual Supplement gives quinolones one sentence, and that sentence is enough. Keep it where the next prescriber can hear it.
Frequently asked questions.
Can Cipro cause these symptoms in someone who has never taken a benzodiazepine?
It can cause some of them. The ciprofloxacin label lists anxiety, agitation, insomnia, nightmares, and confusion as possible reactions and warns that the drug can trigger seizures. Those are effects of the antibiotic itself, not benzodiazepine withdrawal, and they deserve a call to the prescriber all the same.
Will taking an extra benzodiazepine dose cancel out the antibiotic?
Not safely on your own, and the Supplement does not say that it would. The problem is the antibiotic sitting at the binding site, and any change in benzodiazepine dose during a taper needs the prescriber’s hand on it. The fix is the antibiotic, not the benzodiazepine.
This article is educational. It is not medical advice, and reading it does not create a doctor-patient relationship. Decisions about starting, continuing, or tapering any medication should be made with your own physician.
