Spectrum of bacterial susceptibility
Aerobic Gram-positive bacteria

Staphylococcus aureus
Streptococcus pneumoniae
Streptococcus pyogenesAerobic Gram-negative bacteria

Haemophilus parainfluenzae 
Haemophilus influenzae
Moraxella catarrhalisHelicobacter

Helicobacter pyloriMycobacteria
Mycobacterium avium complex consisting of:

Mycobacterium avium avium
Mycobacterium intracellulareOther bacteria

Chlamydia pneumoniae
Mycoplasma pneumoniaeSafety and effectiveness of clarithromycin in treating clinical infections due to the following bacteria have not been established in adequate and well-controlled clinical trials:Aerobic Gram-positive bacteria

Streptococcus agalactiae
Streptococcus (Groups C, F, G)
Viridans group streptococciAerobic Gram-negative bacteria

Bordetella pertussis
Legionella pneumophila
Pasteurella multocidaAnaerobic Gram-positive bacteria

Clostridium perfringens
Peptococcus Niger
Cutibacterium acnesAnaerobic Gram-negative bacteria

Prevotella melaninogenica (formerly Bacteroides melaninogenicus)

Contraindications
Clarithromycin should not be taken by people who are allergic to other macrolides or inactive ingredients in the tablets, including microcrystalline cellulose, croscarmelose sodium, magnesium stearate, and povidone
Clarithromycin should not be used by people with a history of cholestatic jaundice and/or liver dysfunction associated with prior clarithromycin use. Clarithromycin should not be used in the setting of hypokalaemia (low blood potassium)
Use of clarithromycin with the following medications: cisapride, pimozide, astemizole, terfenadine, ergotamine, ticagrelor, ranolazine or dihydroergotamine is not recommended. It should not be used with colchicine in people with kidney or liver impairment. Concomitant use with cholesterol medications such as lovastatin or simvastatin. Hypersensitivity to clarithromycin or any component of the product, erythromycin, or any macrolide antibiotics. QT prolongation or ventricular cardiac arrhythmias, including torsade de pointes. Side effects
The most common side effects are gastrointestinal: diarrhea (3%), nausea (3%), abdominal pain (3%), and vomiting (6%). It also can cause headaches, insomnia, and abnormal liver function tests. Allergic reactions include rashes and anaphylaxis.
Exostoses arising from the posterior aspect of the iliac bones ("iliac horns") are present in as many as 80% of patients; this finding is considered pathognomonic for the syndrome. Other reported bone changes include scoliosis, scapular hypoplasia, and the presence of cervical ribs. Glaucoma is also closely associated with nail-patella, specifically open-angled glaucoma (OAG). Side affects may include frequent headaches, blurred vision, or total vision loss. This occurs gradually over time and symptoms may not be evident in children.Kidney issues may arise such as deposition of protein in the urine and nephritis. Proteinuria is usually the first sign of kidney involvement. It can reveal itself either rapidly or years after having asymptomatic deposition of protein in the urine, kidney failure occurs in around 5% of NPS patients. Hypothyroidism, irritable bowel syndrome, attention deficit hyperactivity disorder (ADHD), and thin tooth enamel are associated with NPS, but whether these are related or simply coincidences are unclear. Genetics
Nail–patella syndrome is inherited via autosomal dominancy linked to aberrancy on human chromosome 9s q arm  (the longer arm), 9q34. This autosomal dominancy means that only a single copy, instead of both, is sufficient for the disorder to be expressed in the offspring, meaning the chance of getting the disorder from an affected heterozygous parent is 50%. The frequency of the occurrence is 1/50,000. The disorder is linked to the ABO blood group locus.It is associated with random mutations in the LMX1B gene. Studies have been conducted and 83 mutations of this gene have been identified.