Don't deny it, we all have one of those friends.
The friend you fell in love with and then slowly but surely you grew to envy, resent, or even loathe. I won't lie, I myself have one. She's arrogant, unkind, and entitled. However, that's not her whole person; she's also intelligent and funny. These friends are unavoidable. You can't predict that they have a secret self that happens to be the definition of all things that you despise. Maybe she's over-sensitive, or has a temper that rivals that of a Spanish bull. Either way, you have two options: coping with said individual, or cutting the ties.
If you plan on coping, here are some helpful methods in doing so:
1. If you are a person who is comfortable with confrontation. I highly suggest sitting down and addressing the issues you're having with said friend. Remember, they might not realize that their behavior is having a negative impact on your friendship, and maybe, they just need to hear it. Things to keep in mind: Your friend is either going to work on things or they won't; this method really depends on their willingness to improve themselves. Don't forget to be kind. Just because they might not be (especially in the case of my friend) doesn't mean you have to degrade him/her. Yelling and insults are only going to make an argument worse and distance you two even further.
2. A secondary coping method is that of limiting your time with the individual. Sometimes, dosage can be the issue, and maybe you just need a break. This works well for those that have overly chatty friends or people who have incredibly strong personalities and opinions. Try taking a break. Give yourself a day or two in between hanging out, and don't hang out more than a few hours at a maximum.
If none of the above methods seem to be working, it's time to ask yourself, "is this person worth having in my life?" If you had to write out a "PROS vs. CONS" list, and that individual is racking up way more cons, why are you keeping them around? Are they a childhood friend that holds sentimental value, or are they someone you're expected to like because the people around you do? I hate to break it to you, but any answer that isn't "because I like them" isn't the right reason to keep someone in your life. Luckily, my problem-friend got rid of herself. She stopped calling and texting me when I didn't go out of my way to compliment her or pay attention to her whining, but some friends won't. Some of them will demand answers, which they are entitled to have. If you plan on cutting loose, remember that kindness and honesty are the best policy. Being real but not hurtful is so incredibly important. You're being given an opportunity to shed some light on them and their personality or habits. This is something they could apply in the future, even if you're not willing to wait to see the potential results.
Finally, ask some serious questions about yourself; are you a friend that might not be easy to have? How can you improve upon that? Are you a Rachel, or maybe you're a Phoebe? Self improvement is something anyone can practice in any stage of life and it can only be beneficial!