Direct answer:

s/[",]//g
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But that's a poor solution. Splitting and dequoting are two separate operations which work on different inputs. It doesn't make much sense to combine them. A better solution:

#!/usr/bin/perl

use strict;
use warnings;

my $string = 'Apropovir,"Atripla(tenofovir+emtricitabine+ efavirenz)",
+';

my @tokens = split(/,/, $string);
s/^"//, s/"$// for @tokens;

for my $token (@tokens) {
   print "$token\n";
}
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But the splitting is still problematic. What if there's a comma in the quotes? You should be using Text::CSV_XS.