I have acne and currently taking antibiotic for the 4th time. am i possible have developed resistance and what is the alternative?

You may need more: An antibiotic should not be used as sole therapy for acne. And for yo, it may not be sufficient. If your acne has produced scarring, something stronger -- perhaps even Isotretinoin -- may be required. Sometimes the oral contracetive pill, if right for you, clears a young woman completely; spironolactone is sometimes overlooked but may work.