Rx Facts
Follow for reliable medical insights!
โ๐ Rx Facts: Your daily dose of pharmacy and pharmacology. >
๐ฌ Simplifying drugs, medical lectures, and healthcare essentials. >
๐ Knowledge at your fingertips.
Chemistry of Quinolones with Emphasis on Structure-Activity Relationship (SAR):
1. Basic Structure:
Quinolones are synthetic antibacterial agents derived from 4-quinolone or *aphthyridone nuclei. The core structure consists of:
- A bicyclic ring: Quinoline nucleus (benzene + pyridine ring)
- A carboxylic acid group at position 3
- A keto group at position 4
Together, the 3-carboxy-4-keto system is essential for DNA gyrase inhibition, which is the main antibacterial action.
2. Fluoroquinolones
The addition of a fluorine atom at position 6 increases:
- Lipophilicity
- Bacterial cell wall pe*******on
- Potency
3. Key SAR Highlights:
- N-1 Substitution: Influences potency and spectrum. E.g., cyclopropyl increases activity against Gram-negatives.
- C-3 Carboxyl + C-4 Keto group: Crucial for binding to DNA gyrase/topoisomerase IV.
- C-5 Substitution: Modulates anti-Gram-positive activity (less common).
- C-6 Fluorine: Enhances activity and cell pe*******on (defines fluoroquinolones).
- C-7 Piperazine or other heterocycles: Improves activity against Gram-negatives and atypical bacteria (e.g., respiratory pathogens).
- C-8 Substitution: Can influence pharmacokinetics and spectrum (e.g., methoxy group reduces phototoxicity).
4. Generations of Quinolones:
- 1st Gen (e.g., Nalidixic acid): Narrow spectrum
- 2nd Gen (e.g., Ciprofloxacin): Broad Gram-negative activity
- 3rd Gen (e.g., Levofloxacin): Better Gram-positive coverage
- 4th Gen (e.g., Moxifloxacin): Anaerobic and enhanced Gram-positive activity
Conclusion:
SAR studies guide the design of newer quinolones with improved potency, broader spectrum, and fewer side effects by modifying specific positions on the quinolone nucleus.
- N-1 Substitution: Influences potency and spectrum. E.g., cyclopropyl increases activity against Gram-negatives.
- C-3 Carboxyl + C-4 Keto group: Crucial for binding to DNA gyrase/topoisomerase IV.
- C-5 Substitution: Modulates anti-Gram-positive activity (less common).
- C-6 Fluorine: Enhances activity and cell pe*******on (defines fluoroquinolones).
- C-7 Piperazine or other heterocycles: Improves activity against Gram-negatives and atypical bacteria (e.g., respiratory pathogens).
- C-8 Substitution: Can influence pharmacokinetics and spectrum (e.g., methoxy group reduces phototoxicity).
26/12/2025
Sickle cell anaemia is a genetic blood disorder in which the body produces abnormal hemoglobin, called hemoglobin S. This causes red blood cells to become rigid, sticky, and shaped like a crescent or sickle, instead of being round and flexible.
These sickled cells:
- Block blood flow in small vessels
- Break down prematurely, leading to anemia
- Cause pain (called sickle cell crises)
- Can damage organs over time
It is inherited when a person receives two sickle cell genesโone from each parent. Itโs most common in people of African, Mediterranean, Middle Eastern, and Indian ancestry.
23/12/2025
Peptic Ulcer Disease (PUD) is a condition where sores (ulcers) develop in the inner lining of the stomach, duodenum (first part of the small intestine), or sometimes the esophagus, due to the damaging effects of stomach acid and pepsin.
Main Causes:
- Helicobacter pylori (H. pylori)* infection
- NSAIDs (e.g. ibuprofen, aspirin)
- Excess acid production (e.g. Zollinger-Ellison syndrome)
- Smoking, alcohol, stress (aggravating factors)
Common Symptoms:
- Burning or gnawing pain in the upper abdomen
- Pain relieved or worsened by eating
- Bloating, nausea, or vomiting
- In severe cases: bleeding, weight loss, or perforation.
Medical Medium
Pharmacy Technician Certification Board (PTCB)
Medicare
ยฉ๐ด๐ฌ๐ซ๐ฐ๐ช๐จ๐ณ ๐จ๐บ๐ท๐ฐ๐น๐จ๐ต๐ป๐บ ๐ฉ๐น๐จ๐ฐ๐ต๐บ๐ป๐ถ๐น๐ด๐ฐ๐ต๐ฎ ๐ฎ๐น๐ถ๐ผ๐ท
21/12/2025
ABSTRACT
Cinnamaldehyde and 4-fluoroaniline are biologically relevant aromatic compounds known for their antioxidant and anti-inflammatory activities. In this study, novel hybrid compounds were synthesized by the condensation of cinnamaldehyde with 4-fluoroaniline, and the resulting products were purified and characterized using UV-Visible, FTIR spectroscopy, melting point determination, solubility profiling and TLC. FTIR data confirmed the presence of key functional groups including C=O, C=C and aromatic ring vibrations, with shifts indicating successful complex formation. UV-Vis spectral features showed bathochromic shifts consistent with increased conjugation and Schiff base (C=N) formation. The biological activities of the synthesized complexes were evaluated in vitro using the DPPH radical scavenging assay and the egg albumin protein denaturation method. The results revealed concentration-dependent antioxidant and anti-inflammatory activities, with some complexes demonstrating ICโ
โ values approaching those of the standard controls (Vitamin C and Aspirin). These findings show that structural hybridisation of cinnamaldehyde with fluorinated amines enhances biological potency by combining electron-rich conjugation with fluorine-assisted pharmacokinetic stability. Therefore, the cinnamaldehydeโ4-fluoroaniline derivatives obtained in this study represent promising lead candidates for future development of multifunctional therapeutic agents targeting oxidative stress and inflammation-associated disorders. Further studies should focus on molecular docking, cytotoxicity profiling and in vivo validation.
20/12/2025
Acute back pain is sudden-onset pain in the back, typically lasting *less than 6 weeks. It often results from:
- Muscle strain or ligament sprain
- Poor posture
- Heavy lifting or sudden movement
- Falls or trauma
Key Features:
- Localized pain (usually lower back)
- May be sharp, dull, or throbbing
- Can limit movement or flexibility
- Usually improves with rest, physical therapy, or medication
If pain persists beyond 6 weeks, it may be considered subacute or chronic and should be evaluated further.
20/12/2025
Vaginal discharge refers to the fluid secreted by glands in the cervix and vaginal walls. It plays an essential role in maintaining vaginal health by:
- Cleansing the vaginal canal
- Providing lubrication
-Maintaining normal pH
- Protecting against infections
Normal discharge:
- Typically clear or whitish
- Mild or no odor
- Varies in consistency and amount depending on the menstrual cycle, hormonal changes, or sexual arousal
Abnormal discharge may indicate an underlying condition and is often:
- Yellow, green, grey, or curd-like
- Accompanied by a strong or unpleasant odor
- Associated with symptoms like itching, burning, irritation, or discomfort
Persistent or unusual changes in vaginal discharge should be evaluated by a healthcare professional for appropriate diagnosis and treatment.
19/12/2025
in .
Example:
Rx
Susp. Quinine 10mg/kg t.d.s x 5/7.
Weight of the child =8kg.
Solution
10mg --------1kg
X ---------------8kg
By Cross Multiplying
X x 1kg =10mg x 8kg
X = 10mg x 8kg/ 1kg
= 80mg.
From the prescription, the frequency of administration is 3 times a day, and the duration of therapy is 5 days, then,
ยฐโขยฐ 80mg x 3 x 5 = 1200mg
To find the number of Quinine tabs to be use
ยฐโขยฐ each Quinine tab is 300mg
Then,
1200mg/300mg
= 4tabs of Quinine.
-> Volume of Vitamin B complex needed.
5ml x 3 x 5 = 75ml
You're to use 4 tabs of quine with 75mls of Vitamin B complex
Each 5mls will contains 80mg of Quinine.
19/12/2025
Definition: is a rare virus disease especially of central and western Africa that is caused by a poxvirus (species Monkeypox virus of the genus Orthopoxvirus), occurs chiefly in wild rodents and primates, and when transmitted to humans resembles smallpox but is milder.
We're back
Expect more from us now
18/03/2023
Gastrointestinal drugs
Click here to claim your Sponsored Listing.
Category
Telephone
Website
Address
Gombe