💊Ciprofloxacin - Fluoroquinolones

August 30, 2019 - 3 min read 🍵🍵

Tags: lifebiochemistry

Disclaimer: This post is strictly for informational purpose and contains the contents of my personal experience, opinion and research I found on the internet and should not be considered medical advice. Please consult your doctor or other qualified healthcare providers for any questions regarding your condition.

It’s almost the end of August with an infection I’ve been trying to kill off since July, almost 5 antibiotics later and I’m back on these two bad boys, metronidazole and ciprofloxacin.

Why does Ciprofloxacin make me so tired?

When you start Googling symptoms, it’s always the most extreme and worst-case scenarios, it’s always important to go to your medical professional to be diagnosed.

However, once diagnosed, I thought it would be beneficial to do extra research on what’s going in my body. Ultimately, I try to figure out the answers to my curious mind and unfortunately, found more than I would like.


Ciprofloxacin is an antibiotic that falls under the class of quinolones used to treat common bacterial infections. Fluoroquinolones kill bacteria by binding to a bacterial enzyme called DNA-gyrase which is responsible for its DNA replication and repairs[1].


There are some adverse side effects of fluoroquinolones which include the central nervous system (CNS). Quinolones can enter the brain tissue readily which causes side effects such as mild headaches, drowsiness and dizziness[2].

In addition to ciprofloxacin, combining it with metronidazole makes it a very effective drug therapy for the treatment of aerobic and anaerobic infections[3]. Metronidazole’s common side effect includes drowsiness as well. It penetrates the blood-brain barrier which adds to the drowsiness[4]. I guess it’s a double whammy.

Serious Side Effects

I definitely found some interesting things about ciprofloxacin especially their serious adverse side effects of developing tendinitis and how it can cause problems affecting tendons in your shoulder, hand and the back of your ankle[5].

Fluoroquinolones increase the chance of Achilles tendon rupture[6]. It may even cause nerve damage long after you’ve taken this antibiotic. That was definitely something I was not expecting.

Ciprofloxacin inhibits mitochondrial DNA synthesis and affects cellular growth and differentiation. These symptoms could be due to oxidative stress. The interference of ciprofloxacin with differentiation processes includes spermatogenesis, brain development and bone mineralization.

However, these mechanisms remain unclear and there is evidence that mitochondria impairment might be the reason for disturbed cellular physiology[7].

Ciprofloxacin is one of the most widely used antibiotics worldwide and recently in 2016, the FDA made a warning announcement regarding the use of fluoroquinolones. The clinical use of fluoroquinolones definitely has been considered; the FDA says for serious bacterial infections, the benefits outweigh the risk and the usage is an appropriate course of treatment.

There will always be side effects to medication and people will have different responses. I just happen to doze off more with these and it helps with having some good rest. If I ever start having tendon problems in the future (knock on wood) I’ll know my answer!

© 2023, Built with ❤ and created with Gatsby